liu.seSök publikationer i DiVA
Ändra sökning
Avgränsa sökresultatet
1234 1 - 50 av 177
RefereraExporteraLänk till träfflistan
Permanent länk
Referera
Referensformat
  • apa
  • harvard1
  • ieee
  • modern-language-association-8th-edition
  • vancouver
  • oxford
  • Annat format
Fler format
Språk
  • de-DE
  • en-GB
  • en-US
  • fi-FI
  • nn-NO
  • nn-NB
  • sv-SE
  • Annat språk
Fler språk
Utmatningsformat
  • html
  • text
  • asciidoc
  • rtf
Träffar per sida
  • 5
  • 10
  • 20
  • 50
  • 100
  • 250
Sortering
  • Standard (Relevans)
  • Författare A-Ö
  • Författare Ö-A
  • Titel A-Ö
  • Titel Ö-A
  • Publikationstyp A-Ö
  • Publikationstyp Ö-A
  • Äldst först
  • Nyast först
  • Skapad (Äldst först)
  • Skapad (Nyast först)
  • Senast uppdaterad (Äldst först)
  • Senast uppdaterad (Nyast först)
  • Disputationsdatum (tidigaste först)
  • Disputationsdatum (senaste först)
  • Standard (Relevans)
  • Författare A-Ö
  • Författare Ö-A
  • Titel A-Ö
  • Titel Ö-A
  • Publikationstyp A-Ö
  • Publikationstyp Ö-A
  • Äldst först
  • Nyast först
  • Skapad (Äldst först)
  • Skapad (Nyast först)
  • Senast uppdaterad (Äldst först)
  • Senast uppdaterad (Nyast först)
  • Disputationsdatum (tidigaste först)
  • Disputationsdatum (senaste först)
Markera
Maxantalet träffar du kan exportera från sökgränssnittet är 250. Vid större uttag använd dig av utsökningar.
  • 1.
    Abbasi, Mazhar Ali
    et al.
    Linköpings universitet, Institutionen för teknik och naturvetenskap, Fysik och elektroteknik. Linköpings universitet, Tekniska högskolan.
    Hussain Ibupoto, Zafar
    Linköpings universitet, Institutionen för teknik och naturvetenskap, Fysik och elektroteknik. Linköpings universitet, Tekniska högskolan.
    Hussain, Mushtaque
    Linköpings universitet, Institutionen för teknik och naturvetenskap, Fysik och elektroteknik. Linköpings universitet, Tekniska högskolan.
    Pozina, Galia
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Tunnfilmsfysik. Linköpings universitet, Tekniska högskolan.
    Lu, Jun
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Tunnfilmsfysik. Linköpings universitet, Tekniska högskolan.
    Hultman, Lars
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Tunnfilmsfysik. Linköpings universitet, Tekniska högskolan.
    Nur, Omer
    Linköpings universitet, Institutionen för teknik och naturvetenskap, Fysik och elektroteknik. Linköpings universitet, Tekniska högskolan.
    Willander, Magnus
    Linköpings universitet, Institutionen för teknik och naturvetenskap, Fysik och elektroteknik. Linköpings universitet, Tekniska högskolan.
    Decoration of ZnO nanorods with coral reefs like NiO nanostructures by the hydrothermal growth method and their luminescence study2014Ingår i: Materials, ISSN 1996-1944, E-ISSN 1996-1944, Vol. 7, nr 1, s. 430-440Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Composite nanostructures of coral reefs like p-type NiO on n-type ZnO nanorods have been decorate on fluorine-doped tin oxide glass substrates by the hydrothermal growth. Structural characterization was performed by field emission scanning electron microscopy,  high-resolution transmission electron microscopy and X-ray diffraction techniques. This investigation has shown that the adopted synthesis has led to high crystalline quality nanostructures. Morphological study shows that the coral reefs like nanostructures are densely packed on the ZnO nanorods. Cathodoluminescence (CL) spectra for the synthesized composite nanostructures were dominated by a near band gap emission at 380 nm and by a broad interstitial defect related luminescence centered at ~630 nm. Spatially resolved CL images reveal that the luminescence originates mainly from the ZnO nanorods.

  • 2.
    Anasori, Babak
    et al.
    Drexel University, PA 19104 USA; Drexel University, PA 19104 USA.
    Dahlqvist, Martin
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Tunnfilmsfysik. Linköpings universitet, Tekniska fakulteten.
    Halim, Joseph
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Tunnfilmsfysik. Linköpings universitet, Tekniska fakulteten. Drexel University, PA 19104 USA.
    Ju Moon, Eun
    Drexel University, PA 19104 USA.
    Lu, Jun
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Tunnfilmsfysik. Linköpings universitet, Tekniska fakulteten.
    Hosler, Brian C.
    Drexel University, PA 19104 USA.
    Caspi, Elad N.
    Drexel University, PA 19104 USA; Nucl Research Centre Negev, Israel.
    May, Steven J.
    Drexel University, PA 19104 USA.
    Hultman, Lars
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Tunnfilmsfysik. Linköpings universitet, Tekniska fakulteten.
    Eklund, Per
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Tunnfilmsfysik. Linköpings universitet, Tekniska fakulteten.
    Rosén, Johanna
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Tunnfilmsfysik. Linköpings universitet, Tekniska fakulteten.
    Barsoum, Michel W.
    Drexel University, PA 19104 USA.
    Experimental and theoretical characterization of ordered MAX phases Mo2TiAlC2 and Mo2Ti2AlC32015Ingår i: Journal of Applied Physics, ISSN 0021-8979, E-ISSN 1089-7550, Vol. 118, nr 9, s. 094304-Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Herein, we report on the phase stabilities and crystal structures of two newly discovered ordered, quaternary MAX phases-Mo2TiAlC2 and Mo2Ti2AlC3-synthesized by mixing and heating different elemental powder mixtures of mMo:(3-m) Ti:1.1Al:2C with 1.5 less than= m less than= 2.2 and 2Mo: 2Ti:1.1Al:2.7C to 1600 degrees C for 4 h under Ar flow. In general, for m greater than= 2 an ordered 312 phase, (Mo2Ti) AlC2, was the majority phase; for mless than 2, an ordered 413 phase (Mo2Ti2)AlC3, was the major product. The actual chemistries determined from X-ray photoelectron spectroscopy (XPS) are Mo2TiAlC1.7 and Mo2Ti1.9Al0.9C2.5, respectively. High resolution scanning transmission microscopy, XPS and Rietveld analysis of powder X-ray diffraction confirmed the general ordered stacking sequence to be Mo-Ti-Mo-Al-Mo-Ti-Mo for Mo2TiAlC2 and Mo-Ti-Ti-Mo-Al-Mo-Ti-Ti-Mo for Mo2Ti2AlC3, with the carbon atoms occupying the octahedral sites between the transition metal layers. Consistent with the experimental results, the theoretical calculations clearly show that M layer ordering is mostly driven by the high penalty paid in energy by having the Mo atoms surrounded by C in a face-centered configuration, i.e., in the center of the Mn+1Xn blocks. At 331 GPa and 367 GPa, respectively, the Youngs moduli of the ordered Mo2TiAlC2 and Mo2Ti2AlC3 are predicted to be higher than those calculated for their ternary end members. Like most other MAX phases, because of the high density of states at the Fermi level, the resistivity measurement over 300 to 10K for both phases showed metallic behavior. (C) 2015 AIP Publishing LLC.

  • 3.
    Anasori, Babak
    et al.
    Drexel University, PA 19104 USA.
    Halim, Joseph
    Linköpings universitet, Tekniska högskolan. Linköpings universitet, Institutionen för fysik, kemi och biologi, Tunnfilmsfysik. Drexel University, USA.
    Lu, Jun
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Tunnfilmsfysik. Linköpings universitet, Tekniska högskolan.
    Voigt, Cooper A.
    Drexel University, PA 19104 USA.
    Hultman, Lars
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Tunnfilmsfysik. Linköpings universitet, Tekniska högskolan.
    Barsoum, Michel W.
    Drexel University, PA 19104 USA.
    Mo2TiAlC2: A new ordered layered ternary carbide2015Ingår i: Scripta Materialia, ISSN 1359-6462, E-ISSN 1872-8456, Vol. 101, s. 5-7Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Herein we report on the synthesis of a new layered ternary carbide, Mo2TiAlC2, that was synthesized by heating an elemental mixture at 1600 degrees C for 4 h under an Ar flow. Its hexagonal, a and c lattice parameters were calculated via Rietveld analysis of powder X-ray diffraction patterns to be, respectively, 2.997 angstrom and 18.661 angstrom. High-resolution scanning transmission electron microscopy showed that this phase is ordered, with Ti layers sandwiched between two Mo layers in a M(3)AX(2) type ternary carbide structure. (C) 2015 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.

  • 4.
    Anasori, Babak
    et al.
    Drexel Univ, PA 19104 USA; Drexel Univ, PA 19104 USA.
    Lu, Jun
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Tunnfilmsfysik. Linköpings universitet, Tekniska fakulteten.
    Rivin, Oleg
    Nucl Res Ctr Negev, Israel.
    Dahlqvist, Martin
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Tunnfilmsfysik. Linköpings universitet, Tekniska fakulteten.
    Halim, Joseph
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Tunnfilmsfysik. Linköpings universitet, Tekniska fakulteten.
    Voigt, Cooper
    Drexel Univ, PA 19104 USA.
    Rosén, Johanna
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Tunnfilmsfysik. Linköpings universitet, Tekniska fakulteten.
    Hultman, Lars
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Tunnfilmsfysik. Linköpings universitet, Tekniska fakulteten.
    Barsoum, Michel W.
    Drexel Univ, PA 19104 USA.
    Caspi, Elad N.
    Drexel Univ, PA 19104 USA; Nucl Res Ctr Negev, Israel.
    A Tungsten-Based Nanolaminated Ternary Carbide: (W,Ti)(4)C4-x2019Ingår i: Inorganic Chemistry, ISSN 0020-1669, E-ISSN 1520-510X, Vol. 58, nr 2, s. 1100-1106Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Nanolamellar transition metal carbides are gaining increasing interests because of the recent developments of their twodimensional (2D) derivatives and promising performance for a variety of applications from energy storage, catalysis to transparent conductive coatings, and medicine. To develop more novel 2D materials, new nanolaminated structures are needed. Here we report on a tungsten based nanolaminated ternary phase, (W,Ti)(4)C4-x, synthesized by an Al catalyzed reaction of W, Ti, and C powders at 1600 degrees C for 4 h, under flowing argon. X-ray and neutron diffraction, along with Z-contrast scanning transmission electron microscopy, were used to determine the atomic structure, ordering, and occupancies. This phase has a layered hexagonal structure (P6(3)/mmc) with lattice parameters, a = 3.00880(7) angstrom, and c = 19.5633(6) angstrom and a nominal chemistry of (W,Ti)(4)C4-x (actual chemistry, W2.1(1)Ti1.6(1)C2.6(1)). The structure is comprised of layers of pure W that are also twin planes with two adjacent atomic layers of mixed W and Ti, on either side. The use of Al as a catalyst for synthesizing otherwise difficult to make phases, could in turn lead to the discovery of a large family of nonstoichiometric ternary transition metal carbides, synthesized at relatively low temperatures and shorter times.

    Publikationen är tillgänglig i fulltext från 2020-01-04 16:13
  • 5.
    Anasori, Babak
    et al.
    Drexel University, PA 19104 USA; Drexel University, PA 19104 USA.
    Xie, Yu
    Oak Ridge National Lab, TN 37831 USA.
    Beidaghi, Majid
    Drexel University, PA 19104 USA; Drexel University, PA 19104 USA.
    Lu, Jun
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Tunnfilmsfysik. Linköpings universitet, Tekniska fakulteten.
    Hosler, Brian C.
    Drexel University, PA 19104 USA.
    Hultman, Lars
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Tunnfilmsfysik. Linköpings universitet, Tekniska fakulteten.
    Kent, Paul R. C.
    Oak Ridge National Lab, TN 37831 USA; Oak Ridge National Lab, TN 37831 USA.
    Gogotsi, Yury
    Drexel University, PA 19104 USA; Drexel University, PA 19104 USA.
    Barsoum, Michel W.
    Drexel University, PA 19104 USA.
    Two-Dimensional, Ordered, Double Transition Metals Carbides (MXenes)2015Ingår i: ACS Nano, ISSN 1936-0851, E-ISSN 1936-086X, Vol. 9, nr 10, s. 9507-9516Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    The higher the chemical diversity and structural complexity of two-dimensional (2D) materials, the higher the likelihood they possess unique and useful properties. Herein, density functional theory (DFT) is used to predict the existence of two new families of 2D ordered, carbides (MXenes), MM-2 C-2 and MM-2 C-2(3), where M and M are two different early transition metals. In these solids, M layers sandwich M" carbide layers. By synthesizing Mo2TiC2Tx, Mo2Ti2C3Tx, and Cr2TiC2Tx (where T is a surface termination), we validated the DFT predictions. Since the Mo and Cr atoms are on the outside, they control the 2D flakes chemical and electrochemical properties. The latter was proven by showing quite different electrochemical behavior of Mo2TiC2Tx and Ti3C2Tx. This work further expands the family of 2D materials, offering additional choices of structures, chemistries, and ultimately useful properties.

  • 6.
    Asif, Muhammad H.
    et al.
    Linköpings universitet, Institutionen för teknik och naturvetenskap. Linköpings universitet, Tekniska högskolan.
    Nur, Omer
    Linköpings universitet, Institutionen för teknik och naturvetenskap. Linköpings universitet, Tekniska högskolan.
    Willander, Magnus
    Linköpings universitet, Institutionen för teknik och naturvetenskap. Linköpings universitet, Tekniska högskolan.
    Strålfors, Peter
    Linköpings universitet, Institutionen för klinisk och experimentell medicin, Cellbiologi. Linköpings universitet, Hälsouniversitetet.
    Brännmark, Cecilia
    Linköpings universitet, Institutionen för klinisk och experimentell medicin, Cellbiologi. Linköpings universitet, Hälsouniversitetet.
    Elinder, Fredrik
    Linköpings universitet, Institutionen för klinisk och experimentell medicin, Cellbiologi. Linköpings universitet, Hälsouniversitetet.
    Englund, Ulrika H
    Linköpings universitet, Institutionen för klinisk och experimentell medicin, Cellbiologi. Linköpings universitet, Hälsouniversitetet.
    Lu, Jun
    Linköpings universitet, Institutionen för fysik, kemi och biologi. Linköpings universitet, Tekniska högskolan.
    Hultman, Lars
    Linköpings universitet, Institutionen för fysik, kemi och biologi. Linköpings universitet, Tekniska högskolan.
    Growth and Structure of ZnO Nanorods on a Sub-Micrometer Glass Pipette and Their Application as Intracellular Potentiometric Selective Ion Sensors2010Ingår i: Materials, ISSN 1996-1944, Vol. 3, s. 4657-4667Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    This paper presents the growth and structure of ZnO nanorods on a sub-micrometer glass pipette and their application as an intracellular selective ion sensor. Highly oriented, vertical and aligned ZnO nanorods were grown on the tip of a borosilicate glass capillary (0.7 μm in diameter) by the low temperature aqueous chemical growth (ACG) technique. The relatively large surface-to-volume ratio of ZnO nanorods makes them attractive for electrochemical sensing. Transmission electron microscopy studies show that ZnO nanorods are single crystals and grow along the crystal’s c-axis. The ZnO nanorods were functionalized with a polymeric membrane for selective intracellular measurements of Na

     

    +. The membrane-coated ZnO nanorods exhibited a Na+-dependent electrochemical potential difference versus

    an Ag/AgCl reference micro-electrode within a wide concentration range from 0.5 mM to 100 mM. The fabrication of functionalized ZnO nanorods paves the way to sense a wide range of biochemical species at the intracellular level.

  • 7.
    Bakhit, Babak
    et al.
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Tunnfilmsfysik. Linköpings universitet, Tekniska fakulteten.
    Engberg, David
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Tunnfilmsfysik. Linköpings universitet, Tekniska fakulteten.
    Lu, Jun
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Tunnfilmsfysik. Linköpings universitet, Tekniska fakulteten.
    Rosén, Johanna
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Tunnfilmsfysik. Linköpings universitet, Tekniska fakulteten.
    Högberg, Hans
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Tunnfilmsfysik. Linköpings universitet, Tekniska fakulteten.
    Hultman, Lars
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Tunnfilmsfysik. Linköpings universitet, Tekniska fakulteten.
    Petrov, Ivan
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Tunnfilmsfysik. Linköpings universitet, Tekniska fakulteten. Univ Illinois, IL 61801 USA.
    Greene, Joseph E
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Tunnfilmsfysik. Linköpings universitet, Tekniska fakulteten. Univ Illinois, IL 61801 USA.
    Greczynski, Grzegorz
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Tunnfilmsfysik. Linköpings universitet, Tekniska fakulteten.
    Strategy for simultaneously increasing both hardness and toughness in ZrB2-rich Zr1-xTaxBy thin films2019Ingår i: Journal of Vacuum Science & Technology. A. Vacuum, Surfaces, and Films, ISSN 0734-2101, E-ISSN 1520-8559, Vol. 37, nr 3, artikel-id 031506Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Refractory transition-metal diborides exhibit inherent hardness. However, this is not always sufficient to prevent failure in applications involving high mechanical and thermal stress, since hardness is typically accompanied by brittleness leading to crack formation and propagation. Toughness, the combination of hardness and ductility, is required to avoid brittle fracture. Here, the authors demonstrate a strategy for simultaneously enhancing both hardness and ductility of ZrB2-rich thin films grown in pure Ar on Al2O3(0001) and Si(001) substrates at 475 degrees C. ZrB2.4 layers are deposited by dc magnetron sputtering (DCMS) from a ZrB2 target, while Zr1-xTaxBy alloy films are grown, thus varying the B/metal ratio as a function of x, by adding pulsed high-power impulse magnetron sputtering (HiPIMS) from a Ta target to deposit Zr1-xTaxBy alloy films using hybrid Ta-HiPIMS/ZrB2-DCMS sputtering with a substrate bias synchronized to the metal-rich portion of each HiPIMS pulse. The average power P-Ta (and pulse frequency) applied to the HiPIMS Ta target is varied from 0 to 1800W (0 to 300 Hz) in increments of 600W (100 Hz). The resulting boron-to-metal ratio, y = B/(Zr+Ta), in as-deposited Zr1-xTaxBy films decreases from 2.4 to 1.5 as P-Ta is increased from 0 to 1800W, while x increases from 0 to 0.3. A combination of x-ray diffraction (XRD), glancing-angle XRD, transmission electron microscopy (TEM), analytical Z-contrast scanning TEM, electron energy-loss spectroscopy, energy-dispersive x-ray spectroscopy, x-ray photoelectron spectroscopy, and atom-probe tomography reveals that all films have the hexagonal AlB2 crystal structure with a columnar nanostructure, in which the column boundaries of layers with 0 amp;lt;= x amp;lt; 0.2 are B-rich, whereas those with x amp;gt;= 0.2 are Ta-rich. The nanostructural transition, combined with changes in average column widths, results in an similar to 20% increase in hardness, from 35 to 42 GPa, with a simultaneous increase of similar to 30% in nanoindentation toughness, from 4.0 to 5.2MPa root m. Published by the AVS.

  • 8.
    Bentzel, Grady W.
    et al.
    Drexel University, PA 19104 USA.
    Naguib, Michael
    Drexel University, PA 19104 USA.
    Lane, Nina J.
    Drexel University, PA 19104 USA.
    Vogel, Sven C.
    Los Alamos National Lab, NM 87545 USA.
    Presser, Volker
    Drexel University, PA 19104 USA.
    Dubois, Sylvain
    University of Poitiers, France.
    Lu, Jun
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Tunnfilmsfysik. Linköpings universitet, Tekniska fakulteten.
    Hultman, Lars
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Tunnfilmsfysik. Linköpings universitet, Tekniska fakulteten.
    Barsoum, Michel W.
    Drexel University, PA 19104 USA.
    Caspi, Elad N.
    Drexel University, PA 19104 USA; Nucl Research Centre Negev, Israel.
    High-Temperature Neutron Diffraction, Raman Spectroscopy, and First-Principles Calculations of Ti3SnC2 and Ti2SnC2016Ingår i: Journal of The American Ceramic Society, ISSN 0002-7820, E-ISSN 1551-2916, Vol. 99, nr 7, s. 2233-2242Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Herein, we report-for the first time-on the additive-free bulk synthesis of Ti3SnC2. A detailed experimental study of the structure of the latter together with a secondary phase, Ti2SnC, is presented through the use of X-ray diffraction (XRD), and high-resolution transmission microscopy (HRTEM). A previous sample of Ti3SnC2, made using Fe as an additive and Ti2SnC as a secondary phase, was studied by high-temperature neutron diffraction (HTND) and XRD. The room-temperature crystallographic parameters of the two MAX phases in the two samples are quite similar. Based on Rietveld analysis of the HTND data, the average linear thermal expansion coefficients of Ti3SnC2 in the a and c directions were found to be 8.5 (2).10(-6) K-1 and 8.9 (1) . 10(-6) K-1, respectively. The respective values for the Ti2SnC phase are 10.1 (3) . 10(-6) K-1 and 10.8 (6) . 10(-6) K-1. Unlike other MAX phases, the atomic displacement parameters of the Sn atoms in Ti3SnC2 are comparable to those of the Ti and C atoms. When the predictions of the atomic displacement parameters obtained from density functional theory are compared to the experimental results, good quantitative agreement is found for the Sn atoms. In the case of the Ti and C atoms, the agreement is more qualitative. We also used first principles to calculate the elastic properties of both Ti2SnC and Ti3SnC2 and their Raman active modes. The latter are compared to experiment and the agreement was found to be good.

  • 9.
    Bostrom, T
    et al.
    Norut No Research Institute Narvik.
    Valizadeh, S
    Uppsala University.
    Lu, Jun
    Linköpings universitet, Institutionen för fysik, kemi och biologi. Linköpings universitet, Tekniska högskolan.
    Jensen, Jens
    Linköpings universitet, Institutionen för fysik, kemi och biologi. Linköpings universitet, Tekniska högskolan.
    Westin, G
    Uppsala University.
    Wackelgard, E
    Uppsala University.
    Structure and morphology of nickel-alumina/silica solar thermal selective absorbers2011Ingår i: JOURNAL OF NON-CRYSTALLINE SOLIDS, ISSN 0022-3093, Vol. 357, nr 5, s. 1370-1375Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Nickel-alumina/silica thin film materials for the use in solar thermal absorbers have been investigated using Scanning Electron Microscopy (SEM), Transmission Electron Microscopy (TEM) and Elastic Recoil Detection Analysis (ERDA). The TEM images revealed that all layers have a very small thickness variation and that the layers are completely homogenous. High resolution images showed 5-10 nm (poly) crystalline nickel nano-particles. ERDA showed that both the silica and alumina compositions contain more oxygen than 2:1 and 3:2 respectively. SEM showed the surface morphology and characteristics of the top silica anti-reflection layer. Hybrid-silica has showed to generate a smoother surface with less cracking compared to pure silica. The final curing temperature revealed to be of importance for the formation of cracks and the surface morphology.

  • 10.
    Broitman, Esteban
    et al.
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Tunnfilmsfysik. Linköpings universitet, Tekniska fakulteten.
    Tengdelius, Lina
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Tunnfilmsfysik. Linköpings universitet, Tekniska fakulteten.
    Hangen, Ude D.
    Hysitron Inc., Minneapolis, Minnesota, USA.
    Lu, Jun
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Tunnfilmsfysik. Linköpings universitet, Tekniska fakulteten.
    Hultman, Lars
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Tunnfilmsfysik. Linköpings universitet, Tekniska fakulteten.
    Högberg, Hans
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Tunnfilmsfysik. Linköpings universitet, Tekniska fakulteten.
    High-temperature nanoindentation of epitaxial ZrB2 thin films2016Ingår i: Scripta Materialia, ISSN 1359-6462, E-ISSN 1872-8456, Vol. 124, s. 117-120Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    We use in-situ heated nanoindentation to investigate the high-temperature nanomechanical properties of epitaxial and textured ZrB2 films deposited by magnetron sputtering. Epitaxial films deposited on 4H-SiC(0001) show a hardness decrease from 47 GPa at room temperature to 33 GPa at 600 °C, while the reduced elastic modulus does not change significantly. High resolution electron microscopy (HRTEM) with selected area electron diffraction of the indented area in a 0001-textured film reveals a retained continuous ZrB2 film and no sign of crystalline phase transformation, despite massive deformation of the Si substrate. HRTEM analysis supports the high elastic recovery of 96% in the films.

  • 11.
    Broitman, Esteban
    et al.
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Tunnfilmsfysik. Linköpings universitet, Tekniska högskolan.
    Yousuf Soomro, Muhammad
    Linköpings universitet, Institutionen för teknik och naturvetenskap. Linköpings universitet, Tekniska högskolan.
    Lu, Jun
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Tunnfilmsfysik. Linköpings universitet, Tekniska högskolan.
    Willander, Magnus
    Linköpings universitet, Institutionen för teknik och naturvetenskap, Fysik och elektroteknik. Linköpings universitet, Tekniska högskolan.
    Hultman, Lars
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Tunnfilmsfysik. Linköpings universitet, Tekniska högskolan.
    Nanoscale piezoelectric response of ZnO nanowires measured using a nanoindentation technique2013Ingår i: Physical Chemistry, Chemical Physics - PCCP, ISSN 1463-9076, E-ISSN 1463-9084, Vol. 15, nr 26, s. 11113-11118Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    We report the piezoelectric properties of ZnO nanowires (NWs) obtained by using a nanoindenter with a conductive boron-doped diamond tip. The direct piezoelectric effect was measured by performing nanoindentations under load control, and the generated piezoelectric voltage was characterized as a function of the applied loads in the range 0.2-6 mN. The converse piezoelectric effect was measured by applying a DC voltage to the sample while there was a low applied force to allow the tip being always in physical contact with the NWs. Vertically aligned ZnO NWs were grown on inexpensive, flexible, and disposable paper substrates using a template-free low temperature aqueous chemical growth method. When using the nanoindenter to measure the direct piezoelectric effect, piezopotential values of up to 26 mV were generated. Corresponding measurement of the converse piezoelectric effect gave an effective piezoelectric coefficient d(33)(eff) of similar to 9.2 pm V-1. The ZnO NWs were also characterized using scanning electron microscopy, X-ray diffraction, and high-resolution transmission electron microscopy. The new nanoindentation approach provides a straightforward method to characterize piezoelectric material deposited on flexible and disposable substrates for the next generation of nanodevices.

  • 12.
    Buchholt, Kristina
    et al.
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Tillämpad Fysik. Linköpings universitet, Tekniska högskolan.
    Eklund, Per
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Tunnfilmsfysik. Linköpings universitet, Tekniska högskolan.
    Jensen, Jens
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Tunnfilmsfysik. Linköpings universitet, Tekniska högskolan.
    Lu, Jun
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Tunnfilmsfysik. Linköpings universitet, Tekniska högskolan.
    Ghandi, R
    Royal Institute Technology, KTH.
    Domeij, M
    Royal Institute Technology, KTH.
    Zetterling, C M
    Royal Institute Technology, KTH.
    Behan, G
    Trinity College Dublin.
    Zhang, H
    Trinity College Dublin.
    Lloyd Spetz, Anita
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Tillämpad Fysik. Linköpings universitet, Tekniska högskolan.
    Hultman, Lars
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Tunnfilmsfysik. Linköpings universitet, Tekniska högskolan.
    Growth and characterization of epitaxial Ti3GeC2 thin films on 4H-SiC(0001)2012Ingår i: Journal of Crystal Growth, ISSN 0022-0248, E-ISSN 1873-5002, Vol. 343, nr 1, s. 133-137Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Epitaxial Ti3GeC2 thin films were deposited on 4 degrees off-cut 4H-SiC(0001) using magnetron sputtering from high purity Ti, C, and Ge targets. Scanning electron microscopy and helium ion microscopy show that the Ti3GeC2 films grow by lateral step-flow with {11 (2) over bar0} faceting on the SiC surface. Using elastic recoil detection analysis, atomic force microscopy, and X-Ray diffraction the films were found to be substoichiometric in Ge with the presence of small Ge particles at the surface of the film.

  • 13.
    Buchholt, Kristina
    et al.
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Tillämpad Fysik. Linköpings universitet, Tekniska högskolan.
    Eklund, Per
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Tunnfilmsfysik. Linköpings universitet, Tekniska högskolan.
    Jensen, Jens
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Tunnfilmsfysik. Linköpings universitet, Tekniska högskolan.
    Lu, Jun
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Tunnfilmsfysik. Linköpings universitet, Tekniska högskolan.
    Lloyd Spetz, Anita
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Tillämpad Fysik. Linköpings universitet, Tekniska högskolan.
    Hultman, Lars
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Tunnfilmsfysik. Linköpings universitet, Tekniska högskolan.
    Step-flow growth of nanolaminate Ti3SiC2 epitaxial layers on 4H-SiC(0 0 0 1)2011Ingår i: SCRIPTA MATERIALIA, ISSN 1359-6462, Vol. 64, nr 12, s. 1141-1144Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Epitaxial Ti3SiC2(0 0 0 1) films were deposited on 4 degrees off-cut 4H-SiC(0 0 0 1) wafers using magnetron sputtering. A lateral step-flow growth mechanism of the Ti3SiC2 was discovered by X-ray diffraction, elastic recoil detection analysis, atomic force microscopy and electron microscopy. Helium ion microscopy revealed contrast variations on the Ti3SiC2 terraces, suggesting a mixed Si and Ti(C) termination. Si-rich growth conditions results in Ti3SiC2 layers with pronounced {1 1 (2) over bar 0) faceting and off-oriented TiSi2 crystallites, while stoichiometric growth yields truncated {1 (1) over bar 0 0) terrace edges.

  • 14.
    Buchholt, Kristina
    et al.
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Tillämpad Fysik. Linköpings universitet, Tekniska högskolan.
    Ghandi, R
    Royal Institute of Technology.
    Domeij, M
    Royal Institute of Technology.
    Zetterling, C-M
    Royal Institute of Technology.
    Lu, Jun
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Tunnfilmsfysik. Linköpings universitet, Tekniska högskolan.
    Eklund, Per
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Tunnfilmsfysik. Linköpings universitet, Tekniska högskolan.
    Hultman, Lars
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Tunnfilmsfysik. Linköpings universitet, Tekniska högskolan.
    Lloyd Spetz, Anita
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Tillämpad Fysik. Linköpings universitet, Tekniska högskolan.
    Ohmic contact properties of magnetron sputtered Ti3SiC2 on n- and p-type 4H-silicon carbide2011Ingår i: Applied Physics Letters, ISSN 0003-6951, E-ISSN 1077-3118, Vol. 98, nr 4, s. 042108-Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Epitaxial Ti3SiC2 (0001) thin film contacts were grown on doped 4H-SiC (0001) using magnetron sputtering in an ultra high vacuum system. The specific contact resistance was investigated using linear transmission line measurements. Rapid thermal annealing at 950 degrees C for 1 min of as-deposited films yielded ohmic contacts to n-type SiC with contact resistances in the order of 10(-4) Omega cm(2). Transmission electron microscopy shows that the interface between Ti3SiC2 and n-type SiC is atomically sharp with evidence of interfacial ordering after annealing.

  • 15.
    Champagne, A.
    et al.
    UCLouvain, Belgium.
    Chaix-Pluchery, O.
    Univ Grenoble Alpes, France.
    Ouisse, T.
    Univ Grenoble Alpes, France.
    Pinek, D.
    Univ Grenoble Alpes, France.
    Gelard, I
    Univ Grenoble Alpes, France.
    Jouffret, L.
    Univ Clermont Auvergne, France.
    Barbier, M.
    Univ Grenoble Alpes, France; European Synchrotron Radiat Facil, France.
    Wilhelm, F.
    European Synchrotron Radiat Facil, France.
    Tao, Quanzheng
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Tunnfilmsfysik. Linköpings universitet, Tekniska fakulteten.
    Lu, Jun
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Tunnfilmsfysik. Linköpings universitet, Tekniska fakulteten.
    Rosén, Johanna
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Tunnfilmsfysik. Linköpings universitet, Tekniska fakulteten.
    Barsoum, M. W.
    Drexel Univ, PA 19104 USA.
    Charlier, J-C
    UCLouvain, Belgium.
    First-order Raman scattering of rare-earth containing i-MAX single crystals (Mo2/3RE1/3)(2)AlC (RE = Nd, Gd, Dy, Ho, Er)2019Ingår i: PHYSICAL REVIEW MATERIALS, ISSN 2475-9953, Vol. 3, nr 5, artikel-id 053609Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Herein, we report on the growth of single crystals of various (Mo2/3RE1/3)(2)AlC (RE = Nd, Gd, Dy, Ho, Er) i-MAX phases and their Raman characterization. Using first principles, the wave numbers of the various phonon modes and their relative atomic displacements are calculated and compared to experimental results. Twelve high-intensity Raman peaks are identified as the fingerprint of this new family of rare-earth containing i-MAX phases, thus being a useful tool to investigate their corresponding composition and structural properties. Indeed, while a redshift is observed in the low-wave-number range due to an increase of the rare-earth atomic mass when moving from left to right on the lanthanide row, a blueshift is observed for most of the high-wave-number modes due to a strengthening of the bonds. A complete classification of bond stiffnesses is achieved based on the direct dependence of a phonon mode wave number with respect to the bond stiffness. Finally, STEM images are used to confirm the crystal structure.

  • 16.
    Chen, Jr-Tai
    et al.
    SweGaN AB, Teknikringen 8D, Linköping, Sweden.
    Bergsten, Johan
    Department of Microtechnology and Nanoscience, Chalmers University of Technology, Gothenburg, Sweden.
    Lu, Jun
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Tunnfilmsfysik. Linköpings universitet, Tekniska fakulteten.
    Janzén, Erik
    SweGaN AB, Teknikringen 8D, Linköping, Sweden.
    Thorsell, Mattias
    Department of Microtechnology and Nanoscience, Chalmers University of Technology, Gothenburg, Sweden.
    Hultman, Lars
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Tunnfilmsfysik. Linköpings universitet, Tekniska fakulteten.
    Rorsman, Niklas
    Department of Microtechnology and Nanoscience, Chalmers University of Technology, Gothenburg, Sweden.
    Kordina, Olof
    SweGaN AB, Teknikringen 8D, Linköping, Sweden.
    A GaN-SiC hybrid material for high-frequency and power electronics2018Ingår i: Applied Physics Letters, ISSN 0003-6951, E-ISSN 1077-3118, Vol. 113, nr 4, artikel-id 041605Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    We demonstrate that 3.5% in-plane lattice mismatch between GaN (0001) epitaxial layers and SiC (0001) substrates can be accommodated without triggering extended defects over large areas using a grain-boundary-free AIN nucleation layer (NL). Defect formation in the initial epitaxial growth phase is thus significantly alleviated, confirmed by various characterization techniques. As a result, a high-quality 0.2-mu m thin GaN layer can be grown on the AIN NL and directly serve as a channel layer in power devices, like high electron mobility transistors (HEMTs). The channel electrons exhibit a state-of-the-art mobility of amp;gt;2000 cm(2)/V-s, in the AlGaN/GaN heterostructures without a conventional thick C- or Fe-doped buffer layer. The highly scaled transistor processed on the heterostructure with a nearly perfect GaN-SiC interface shows excellent DC and microwave performances. A peak RF power density of 5.8 W/mm was obtained at V-DSQ = 40 V and a fundamental frequency of 30 GHz. Moreover, an unpassivated 0.2-mu m GaN/AIN/SiC stack shows lateral and vertical breakdowns at 1.5 kV. Perfecting the GaN-SiC interface enables a GaN-SiC hybrid material that combines the high-electron-velocity thin GaN with the high-breakdown bulk SiC, which promises further advances in a wide spectrum of high-frequency and power electronics.

  • 17.
    Chen, Liugang
    et al.
    Katholieke Univ Leuven, Belgium.
    Dahlqvist, Martin
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Tunnfilmsfysik. Linköpings universitet, Tekniska fakulteten.
    Lapauw, Thomas
    Katholieke Univ Leuven, Belgium; SCK CEN, Belgium.
    Tunca, Bensu
    Katholieke Univ Leuven, Belgium; SCK CEN, Belgium.
    Wang, Fei
    Katholieke Univ Leuven, Belgium.
    Lu, Jun
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Tunnfilmsfysik. Linköpings universitet, Tekniska fakulteten.
    Meshkian, Rahele
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Tunnfilmsfysik. Linköpings universitet, Tekniska fakulteten.
    Lambrinou, Konstantina
    SCK CEN, Belgium.
    Blanpain, Bart
    Katholieke Univ Leuven, Belgium.
    Vleugels, Jozef
    Katholieke Univ Leuven, Belgium.
    Rosén, Johanna
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Tunnfilmsfysik. Linköpings universitet, Tekniska fakulteten.
    Theoretical Prediction and Synthesis of (Cr2/3Zr1/3)(2)AIC i-MAX Phase2018Ingår i: Inorganic Chemistry, ISSN 0020-1669, E-ISSN 1520-510X, Vol. 57, nr 11, s. 6237-6244Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Guided by predictive theory, a new compound with chemical composition (Cr2/3Zr1/3)(2)AlC was synthesized by hot pressing of Cr, ZrH2, Al, and C mixtures at 1300 degrees C. The crystal structure is monoclinic of space group C2/c and displays in-plane chemical order in the metal layers, a so-called i-MAX phase. Quantitative chemical composition analyses confirmed that the primary phase had a (Cr2/3Zr1/3)(2)AlC stoichiometry, with secondary Cr2AlC, AlZrC2, and ZrC phases and a small amount of Al-Cr intermetallics. A theoretical evaluation of the (Cr2/3Zr1/3)(2)AlC magnetic structure was performed, indicating an antiferromagnetic ground state. Also (Cr2/3Zr1/3)(2)AlC, of the same structure, was predicted to be stable.

  • 18.
    Dahlqvist, Martin
    et al.
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Tunnfilmsfysik. Linköpings universitet, Tekniska fakulteten.
    Lu, Jun
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Tunnfilmsfysik. Linköpings universitet, Tekniska fakulteten.
    Meshkian, Rahele
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Tunnfilmsfysik. Linköpings universitet, Tekniska fakulteten.
    Tao, Quanzheng
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Tunnfilmsfysik. Linköpings universitet, Tekniska fakulteten.
    Hultman, Lars
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Tunnfilmsfysik. Linköpings universitet, Tekniska fakulteten.
    Rosén, Johanna
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Tunnfilmsfysik. Linköpings universitet, Tekniska fakulteten.
    Prediction and synthesis of a family of atomic laminate phases with Kagome-like and in-plane chemical ordering2017Ingår i: Science Advances, ISSN 0036-8156, E-ISSN 2375-2548, Vol. 3, nr 7, artikel-id e1700642Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    The enigma of MAX phases and their hybrids prevails. We probe transition metal (M) alloying in MAX phases for metal size, electronegativity, and electron configuration, and discover ordering in these MAX hybrids, namely, (V2/3Zr1/3)(2)AlC and (Mo2/3Y1/3)(2)AlC. Predictive theory and verifying materials synthesis, including a judicious choice of alloying M from groups III to VI and periods 4 and 5, indicate a potentially large family of thermodynamically stable phases, with Kagome-like and in-plane chemical ordering, and with incorporation of elements previously not known for MAX phases, including the common Y. We propose the structure to be monoclinic C2/c. As an extension of the work, we suggest a matching set of novel MXenes, from selective etching of the A-element. The demonstrated structural design on simultaneous two-dimensional (2D) and 3D atomic levels expands the property tuning potential of functional materials.

  • 19.
    Dahlqvist, Martin
    et al.
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Tunnfilmsfysik. Linköpings universitet, Tekniska fakulteten.
    Petruhins, Andrejs
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Tunnfilmsfysik. Linköpings universitet, Tekniska fakulteten.
    Lu, Jun
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Tunnfilmsfysik. Linköpings universitet, Tekniska fakulteten.
    Hultman, Lars
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Tunnfilmsfysik. Linköpings universitet, Tekniska fakulteten.
    Rosén, Johanna
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Tunnfilmsfysik. Linköpings universitet, Tekniska fakulteten.
    Origin of Chemically Ordered Atomic Laminates (i-MAX): Expanding the Elemental Space by a Theoretical/Experimental Approach2018Ingår i: ACS Nano, ISSN 1936-0851, E-ISSN 1936-086X, Vol. 12, nr 8, s. 7761-7770Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    With increased chemical diversity and structural complexity comes the opportunities for innovative materials possessing advantageous properties. Herein, we combine predictive first-principles calculations with experimental synthesis, to explore the origin of formation of the atomically laminated i-MAX phases. By probing (Mo2/3M1/32)(2)AC (where M-2 = Sc, Y and A = Al, Ga, In, Si, Ge, In), we predict seven stable i-MAX phases, five of which should have a retained stability at high temperatures. (Mo2/3Sc1/3)(2)GaC and (Mo2/3Y1/3)(2)GaC were experimentally verified, displaying the characteristic in-plane chemical order of Mo and Sc/Y and Kagome-like ordering of the A-element. We suggest that the formation of i-MAX phases requires a significantly different size of the two metals, and a preferable smaller size of the A-element. Furthermore, the population of antibonding orbitals should be minimized, which for the metals herein (Mo and Sc/Y) means that A elements from Group 13 (Al, Ga, In) are favored over Group 14 (Si, Ge, Sn). Using these guidelines, we foresee a widening of elemental space for the family of i-MAX phases and expect more phases to be synthesized, which will realize useful properties. Furthermore, based on i-MAX phases as parent materials for 2D MXenes, we also expect that the range of MXene compositions will be expanded.

  • 20.
    Eklund, Per
    et al.
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Tunnfilmsfysik. Linköpings universitet, Tekniska högskolan.
    Dahlqvist, Martin
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Tunnfilmsfysik. Linköpings universitet, Tekniska högskolan.
    Tengstrand, Olof
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Tunnfilmsfysik. Linköpings universitet, Tekniska högskolan.
    Hultman, Lars
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Tunnfilmsfysik. Linköpings universitet, Tekniska högskolan.
    Lu, Jun
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Tunnfilmsfysik. Linköpings universitet, Tekniska högskolan.
    Nedfors, Nils
    Uppsala University, Sweden .
    Jansson, Ulf
    Uppsala University, Sweden .
    Rosén, Johanna
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Tunnfilmsfysik. Linköpings universitet, Tekniska högskolan.
    Discovery of the Ternary Nanolaminated Compound Nb2GeC by a Systematic Theoretical-Experimental Approach2012Ingår i: Physical Review Letters, ISSN 0031-9007, E-ISSN 1079-7114, Vol. 109, nr 3, s. 035502-Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Since the advent of theoretical materials science some 60 years ago, there has been a drive to predict and design new materials in silicio. Mathematical optimization procedures to determine phase stability can be generally applicable to complex ternary or higher-order materials systems where the phase diagrams of the binary constituents are sufficiently known. Here, we employ a simplex-optimization procedure to predict new compounds in the ternary Nb-Ge-C system. Our theoretical results show that the hypothetical Nb2GeC is stable, and excludes all reasonably conceivable competing hypothetical phases. We verify the existence of the Nb2GeC phase by thin film synthesis using magnetron sputtering. This hexagonal nanolaminated phase has a and c lattice parameters of similar to 3.24 angstrom and 12.82 angstrom.

  • 21.
    Eklund, Per
    et al.
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Tunnfilmsfysik. Linköpings universitet, Tekniska högskolan.
    Frodelius, Jenny
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Tunnfilmsfysik. Linköpings universitet, Tekniska högskolan.
    Hultman, Lars
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Tunnfilmsfysik. Linköpings universitet, Tekniska högskolan.
    Lu, Jun
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Tunnfilmsfysik. Linköpings universitet, Tekniska högskolan.
    Magnfält, Daniel
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Plasma och beläggningsfysik. Linköpings universitet, Tekniska högskolan.
    Epitaxial growth of gamma-Al2O3 on Ti2AlC(0001) by reactive high-power impulse magnetron sputtering2014Ingår i: AIP Advances, ISSN 2158-3226, E-ISSN 2158-3226, Vol. 4, nr 1, s. 017138-Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Al2O3 was deposited by reactive high-power impulse magnetron sputtering at 600 degrees C onto pre-deposited Ti2AlC(0001) thin films on alpha-Al2O3(0001) substrates. The Al2O3 was deposited to a thickness of 65 nm and formed an adherent layer of epitaxial gamma-Al2O3(111) as shown by transmission electron microscopy. The demonstration of epitaxial growth of gamma-Al2O3 on Ti2AlC (0001) open prospects for growth of crystalline alumina as protective coatings on Ti2AlC and related nanolaminated materials. The crystallographic orientation relationships are gamma-Al2O3(111)//Ti2AlC(0001) (out-of-plane) and gamma-Al2O3(2 (2) over bar0)//Ti2AlC(11 (2) over bar0) (in-plane) as determined by electron diffraction. Annealing in vacuum at 900 degrees C resulted in partial decomposition of the Ti2AlC by depletion of Al and diffusion into and through the gamma-Al2O3 layer.

  • 22.
    Ekström, Erik
    et al.
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Tunnfilmsfysik. Linköpings universitet, Tekniska fakulteten.
    Le Febvrier, Arnaud
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Tunnfilmsfysik. Linköpings universitet, Tekniska fakulteten.
    Fournier, Daniele
    Sorbonne Univ, France.
    Lu, Jun
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Tunnfilmsfysik. Linköpings universitet, Tekniska fakulteten.
    Ene, Vladimir-Lucian
    Linköpings universitet, Institutionen för fysik, kemi och biologi. Linköpings universitet, Tekniska fakulteten. Univ Politehn Bucuresti, Romania.
    Van Nong, Ngo
    Tech Univ Denmark, Denmark.
    Eriksson, Fredrik
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Tunnfilmsfysik. Linköpings universitet, Tekniska fakulteten.
    Eklund, Per
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Tunnfilmsfysik. Linköpings universitet, Tekniska fakulteten.
    Paul, Biplab
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Tunnfilmsfysik. Linköpings universitet, Tekniska fakulteten.
    Formation mechanism and thermoelectric properties of CaMnO3 thin films synthesized by annealing of Ca0.5Mn0.5O films2019Ingår i: Journal of Materials Science, ISSN 0022-2461, E-ISSN 1573-4803, Vol. 54, nr 11, s. 8482-8491Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    A two-step synthesis approach was utilized to grow CaMnO3 on M-, R- and C-plane sapphire substrates. Radio-frequency reactive magnetron sputtering was used to grow rock-salt-structured (Ca, Mn)O followed by a 3-h annealing step at 800 degrees C in oxygen flow to form the distorted perovskite phase CaMnO3. The effect of temperature in the post-annealing step was investigated using x-ray diffraction. The phase transformation to CaMnO3 started at 450 degrees C and was completed at 550 degrees C. Films grown on R- and C-plane sapphire showed similar structure with a mixed orientation, whereas the film grown on M-plane sapphire was epitaxially grown with an out-of-plane orientation in the [202] direction. The thermoelectric characterization showed that the film grown on M-plane sapphire has about 3.5 times lower resistivity compared to the other films with a resistivity of 0.077cm at 500 degrees C. The difference in resistivity is a result from difference in crystal structure, single orientation for M-plane sapphire compared to mixed for R- and C-plane sapphire. The highest absolute Seebeck coefficient value is -350 mu VK-1 for all films and is decreasing with temperature.

  • 23.
    Elhag, Sami
    et al.
    Linköpings universitet, Institutionen för teknik och naturvetenskap. Linköpings universitet, Tekniska fakulteten.
    Tordera, Daniel
    Linköpings universitet, Institutionen för teknik och naturvetenskap. Linköpings universitet, Tekniska fakulteten.
    Deydier, T
    Department of Material Engineering, University of Toulon, FR-83041 Toulon, France .
    Lu, Jun
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Tunnfilmsfysik. Linköpings universitet, Tekniska fakulteten.
    LiU, Xianjie
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Tunnfilmsfysik. Linköpings universitet, Tekniska fakulteten.
    Khranovskyy, Volodymyr
    Linköpings universitet, Tekniska fakulteten. Linköpings universitet, Institutionen för fysik, kemi och biologi, Tunnfilmsfysik.
    Hultman, Lars
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Tunnfilmsfysik. Linköpings universitet, Tekniska fakulteten.
    Willander, Magnus
    Linköpings universitet, Institutionen för teknik och naturvetenskap, Fysik och elektroteknik. Linköpings universitet, Tekniska fakulteten.
    Jonsson, Magnus
    Linköpings universitet, Institutionen för teknik och naturvetenskap, Fysik och elektroteknik. Linköpings universitet, Tekniska fakulteten.
    Nur, Omer
    Linköpings universitet, Institutionen för teknik och naturvetenskap, Fysik och elektroteknik. Linköpings universitet, Tekniska fakulteten.
    Low-temperature growth of polyethylene glycol-doped BiZn2VO6 nanocompounds with enhanced photoelectrochemical properties2017Ingår i: Journal of Materials Chemistry A, ISSN 2050-7488, Vol. 5, nr 3, s. 1112-1119Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    We demonstrate scalable, low-cost and low-temperature (<100 °C) aqueous chemical growth of bismuth–zinc vanadate (BiZn2VO6) nanocompounds by BiVO4 growth on ZnO nanobelts (NBs). The nanocompounds were further doped with polyethylene glycol (PEG) to tune the electronic structure of the materials, as a means to lower the charge carrier recombination rate. The chemical composition, morphology, and detailed nanostructure of the BiZn2VO6 nanocompounds were characterized. They exhibit rice-like morphology, are highly dense on the substrate and possess a good crystalline quality. Photoelectrochemical characterization in 0.1 M lithium perchlorate in carbonate propylene shows that BiZn2VO6 nanocompounds are highly suitable as anodes for solar-driven photoelectrochemical applications, providing significantly better performance than with only ZnO NBs. This performance could be attributed to the heterogeneous catalysis effect at nanocompound and ZnO NB interfaces, which have enhanced the electron transfer process on the electrode surface. Furthermore, the charge collection efficiency could be significantly improved through PEG doping of nanocompounds. The photocurrent density of PEG-doped BiZn2VO6 nanocompounds reached values of 2 mA cm−2 at 1.23 V (vs. Ag/AgCl), over 60% larger than that of undoped BiZn2VO6 nanocompounds. Photoluminescence emission experiments confirmed that PEG plays a crucial role in lowering the charge carrier recombination rate. The presented BiZn2VO6 nanocompounds are shown to provide highly competitive performance compared with other state-of-the art photoelectrodes.

  • 24.
    Engberg, David L. J.
    et al.
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Tunnfilmsfysik. Linköpings universitet, Tekniska fakulteten.
    Johnson, Lars J. S.
    Sandvik Coromant, Stockholm, Sweden.
    Johansson-­‐Jöesaar, Mats
    Linköpings universitet, Institutionen för fysik, kemi och biologi. Linköpings universitet, Tekniska fakulteten. SECO Tools AB, Fagersta, Sweden.
    Lu, Jun
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Tunnfilmsfysik. Linköpings universitet, Tekniska fakulteten.
    Odén, Magnus
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Nanostrukturerade material. Linköpings universitet, Tekniska fakulteten.
    Thuvander, Mattias
    Department of Applied Physics, Chalmers University of Technology, Göteborg, Sweden.
    Hultman, Lars
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Tunnfilmsfysik. Linköpings universitet, Tekniska fakulteten.
    Solid Solution and Segregation Effects in Arc-Deposited Ti1-xSixN Thin Films Resolved on the nanometer scale by 15N Isotopic Substitution in AtomP robe TomographyManuskript (preprint) (Övrigt vetenskapligt)
    Abstract [en]

    Nanostructured TiSiN is an important material in wear--‐resistant coatings for extending the lifetime of cutting tools. Yet, the understanding regarding the structure, phase composition, and bonding on the detailed nanometer scale, which determines the properties of TiSiN, is lacking. This limits our understanding of the growth phenomena and eventually a larger exploitation of the material. By substituting natN2 with 15N2 during reactive arc deposition of TiSiN thin films, atom probe tomography (APT) gives elemental sensitivity and sub-nanometer resolution, a finer scale than what can be obtained by commonly employed energy dispersive electron spectroscopy in scanning transmission electron microscopy. Using a combination of analytical transmission electron microscopy and APT we show that arc-deposited Ti0.92Si0.0815N and Ti0.81Si0.1915N exhibit Si segregation on the nanometer scale in the alloy films. APT composition maps and proximity histograms from domains with higher than average Ti content show that the TiN domains contain at least ~2 at. % Si for Ti0.92Si0.08N and ~5 at. % Si for Ti0.81Si0.19N, thus confirming the formation of solid solutions. The formation of relatively pure SiNy domains in the Ti0.81Si0.19N films is tied to pockets between microstructured, columnar features in the film. Finer SiNy enrichments seen in APT possibly correspond to tissue layers around TiN crystallites, thus effectively hindering growth of TiN crystallites, causing TiN renucleation and thus explaining the featherlike nanostructure within the columns of these films. For the stoichiometry of the TiN phase, we establish a global under stoichiometry, in accordance with the tendency for SiNy films to have tetrahedral bonding coordination towards a nominal Si3N4 composition.

  • 25.
    Eriksson, Anders
    et al.
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Tunnfilmsfysik. Linköpings universitet, Tekniska högskolan.
    Lu, Jun
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Tunnfilmsfysik. Linköpings universitet, Tekniska högskolan.
    Tengstrand, Olof
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Tunnfilmsfysik. Linköpings universitet, Tekniska högskolan.
    Jensen, Jens
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Tunnfilmsfysik. Linköpings universitet, Tekniska högskolan.
    Eklund, Per
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Tunnfilmsfysik. Linköpings universitet, Tekniska högskolan.
    Rosén, Johanna
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Tunnfilmsfysik. Linköpings universitet, Tekniska högskolan.
    Hultman, Lars
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Tunnfilmsfysik. Linköpings universitet, Tekniska högskolan.
    Nanocolumnar Epitaxial Ti1-xSixN (0 ≤ x ≤ 0.18) Thin Films Grown by Dual Reactive Magnetron Sputtering on MgO (001), (011), and (111) Substrates2012Manuskript (preprint) (Övrigt vetenskapligt)
    Abstract [en]

    Ti1-xSixNy thin films and multilayers have been grown on single-crystal TiN-templated MgO (001), (011), and (111) substrates kept at 550 °C. Elemental Ti and Si targets were used in UVH reactive dual magnetron sputtering in a mixed Ar/N2 discharge. Composition analysis by time-of-flight energy elastic recoil detection analysis show that the films are close to stoichiometric (0.95 ≤ y ≤ 1.00) with respect to TiN over the wide range of Si concentrations 0 ≤ x ≤ 0.22. High-resolution transmission electron microscopy (TEM) combined with scanning TEM and energy dispersive Xray analysis show that all films grow epitaxially for x ≤ 0.18 and that as much as every fifth Ti atom can be replaced by Si (~10 at.%) in Ti1-xSixN(001). For the (011) and (111)-oriented films, however, only 1-2 at.% Si substitutes for Ti. Instead, Si segregates to form crystalline-to-amorphous SiNz (z ≈ 1) tissue phases, which promote the formation of epitaxial TiN nanocolumns. The nanocolumns have preferred {110} interfaces and {200} top facets and grow several hundreds  of nm in length.

  • 26.
    Eriksson, Anders
    et al.
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Tunnfilmsfysik. Linköpings universitet, Tekniska högskolan.
    Tengstrand, Olof
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Tunnfilmsfysik. Linköpings universitet, Tekniska högskolan.
    Lu, Jun
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Tunnfilmsfysik. Linköpings universitet, Tekniska högskolan.
    Jensen, Jens
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Tunnfilmsfysik. Linköpings universitet, Tekniska högskolan.
    Eklund, Per
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Tunnfilmsfysik. Linköpings universitet, Tekniska högskolan.
    Rosén, Johanna
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Tunnfilmsfysik. Linköpings universitet, Tekniska högskolan.
    Petrov, Ivan
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Tunnfilmsfysik. Linköpings universitet, Tekniska högskolan. University of Illinois, IL 61801 USA.
    Greene, Joseph E
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Tunnfilmsfysik. Linköpings universitet, Tekniska högskolan. University of Illinois, IL 61801 USA.
    Hultman, Lars
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Tunnfilmsfysik. Linköpings universitet, Tekniska högskolan.
    Si incorporation in Ti1-xSixN films grown on TiN(001) and (001)-faceted TiN(111) columns2014Ingår i: Surface & Coatings Technology, ISSN 0257-8972, E-ISSN 1879-3347, Vol. 257, s. 121-128Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Thin films consisting of TiN nanocrystallites encapsulated in a fully percolated SiNy tissue phase are archetypes for hard and superhard nanocomposites. Here, we investigate metastable SiNy solid solubility in TiN and probe the effects of surface segregation during the growth of TiSiN films onto substrates that are either flat TiN(001)/MgO(001) epitaxial buffer layers or TiN(001) facets of length 1-5 nm terminating epitaxial TiN(111) nanocolumns, separated by voids, deposited on epitaxial TiN(111)/MgO(111) buffer layers. Using reactive magnetron sputter deposition, the TiSiN layers were grown at 550 degrees C and the TiN buffer layers at 900 degrees C On TiN(001), the films are NaCl-structure single-phase metastable Ti1-xSixN(001) with N/(Ti + Si) = 1 and 0 less than= x less than= 0.19. These alloys remain single-crystalline to critical thicknesses h(c) ranging from 100 +/- 30 nm with x = 0.13 to 40 +/- 10 nm with x = 0.19. At thicknesses h greater than h(c), the epitaxial growth front breaks down locally to form V-shaped polycrystalline columns with an underdense feather-like nanostructure. In contrast, the voided epitaxial TiN(111) columnar surfaces, as well as the TiN(001) facets, act as sinks for SiNy. For Ti1-xSixN layers with global average composition values less than x greater than = 0.16, the local x value in the middle of Ti1-xSixN columns increases from 0.08 for columns with radius r similar or equal to 2 nm to x = 0.14 with r similar or equal to 4 nm. The average out-of-plane lattice parameter of epitaxial nanocolumns encapsulated in SiNy decreases monotonically with increasing Si fraction less than x greater than, indicating the formation of metastable (Ti,Si)N solid solutions under growth conditions similar to those of superhard nanocomposites for which the faceted surfaces of nanograins also provide sinks for SiNy.

  • 27.
    Fager, Hanna
    et al.
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Tunnfilmsfysik. Linköpings universitet, Tekniska högskolan.
    Andersson, J.M.
    Seco Tools AB, SE-737 82 Fagersta, Sweden.
    Jensen, Jens
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Tunnfilmsfysik. Linköpings universitet, Tekniska högskolan.
    Lu, Jun
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Tunnfilmsfysik. Linköpings universitet, Tekniska högskolan.
    Hultman, Lars
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Tunnfilmsfysik. Linköpings universitet, Tekniska högskolan.
    Thermal stability and mechanical properties of amorphous arc evaporated Ti-B-Si-N and Ti-B-Si-Al-N coatings grown by cathodic arc evaporation from TiB2, Ti33Al67, and Ti85Si15 cathodes2014Ingår i: Journal of Vacuum Science & Technology. A. Vacuum, Surfaces, and Films, ISSN 0734-2101, E-ISSN 1520-8559, Vol. 32, nr 6, s. 061508-Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Ti-B-Al-N, Ti-B-Si-N, and Ti-B-Si-Al-N coatings were grown on cemented carbide substrates in an industrial scale cathodic arc evaporation system using Ti33Al67, Ti85Si15, and TiB2 cathodes in a reactiveN2 atmosphere. The microstructure of the as-deposited coatings changes from nanocrystalline to amorphous with addition of (B+Si+Al), or high amounts of (B+Si) to TiN. In the as-deposited state, the 4 μm-thick amorphous coatings are dense and homogenous, besides slight compositional modulation with Ti-rich layers induced by rotation of the substrate holder fixture during deposition, and have unusually few macroparticles. Annealing at temperatures ranging from 700 °C to 1100 °C results in that the coatings crystallize by clustering of TiN grains. The hardness of as-deposited amorphous coatings is 17-18 GPa, and increases to 21 GPa following annealing at 800 °C. At annealing temperatures of 1000 °C and above the hardness decreases due to inter-diffusion of Co from the substrate to the coating.

  • 28.
    Fager, Hanna
    et al.
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Tunnfilmsfysik. Linköpings universitet, Tekniska högskolan.
    Eriksson, Fredrik
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Tunnfilmsfysik. Linköpings universitet, Tekniska högskolan.
    Lu, Jun
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Tunnfilmsfysik. Linköpings universitet, Tekniska högskolan.
    Jensen, Jens
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Tunnfilmsfysik. Linköpings universitet, Tekniska högskolan.
    Hultman, Lars
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Tunnfilmsfysik. Linköpings universitet, Tekniska högskolan.
    Reactive DC magnetron sputtering of amorphous (Ti0.25B0.75)1−xSixNy thin films from TiB2 and Si targets2014Manuskript (preprint) (Övrigt vetenskapligt)
    Abstract [en]

    (Ti0.25B0.75)1−xSixNy, 0≤x≤0.89, 0.9≤y≤1.25, thin films were reactively grown on Si(001) substrates by dc magnetron sputtering from compound TiB2 and elemental Si targets. The films can be grown in a fully electron-diffraction amorphous state with x>0.46, as evidenced by XRD and HR-TEM investigations. With x=0, BN form onion-like sheets surrounding TiNnanograins. Substrate temperatures, Ts=100-600 ◦C, has a minor effect of the film structure and properties, due to limited surface diffusion.

    Ion-assisted growth with substrate bias voltages, Vb, between -50 V and -200 V, favors densification of amorphous structures over nanocrystalline formation, and improves mechanical properties. A maximum hardness value of 26.8±0.7 GPa is found for an amorphous (Ti0.25B0.75)0.39Si0.61N1.15 film grown with substrate temperature Ts=400 °C and substrate bias voltage Vb=-100 V.

  • 29.
    Fager, Hanna
    et al.
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Tunnfilmsfysik. Linköpings universitet, Tekniska högskolan.
    Greczynski, Grzegorz
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Tunnfilmsfysik. Linköpings universitet, Tekniska högskolan.
    Jensen, Jens
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Tunnfilmsfysik. Linköpings universitet, Tekniska högskolan.
    Lu, Jun
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Tunnfilmsfysik. Linköpings universitet, Tekniska högskolan.
    Hultman, Lars
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Tunnfilmsfysik. Linköpings universitet, Tekniska högskolan.
    Growth and properties of amorphous Ti-B-Si-N thin films deposited by hybrid HIPIMS/DC-magnetron co-sputtering from TiB2 and Si targets2014Ingår i: Surface & Coatings Technology, ISSN 0257-8972, E-ISSN 1879-3347, Vol. 259, s. 442-447Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Amorphous nitrides are explored for their homogenous structure and potential use as wear-resistant coatings, beyond their much studied nano-and microcrystalline counterparts. (TiB2)1−xSixNy thin films were deposited on Si(001) substrates by a hybrid technique of high power impulse magnetron sputtering (HIPIMS) combined with dc magnetron sputtering (DCMS) using TiB2 and Si targets in a N2/Ar atmosphere. By varying the sputtering dc power to the Si target from 200 to 2000 W while keeping the average power to the TiB2-target, operated in HIPIMS mode, constant at 4000 W, the Si content in the films increased gradually from x=0.01 to x=0.43. The influence of the Si content on the microstructure, phase constituents, and mechanical properties were systematically investigated. The results show that the microstructure of as-deposited (TiB2)1−xSixNy films changes from nanocrystalline with 2-4 nm TiN grains for x=0.01 to fully electron diffraction amorphous for x=0.22. With increasing Si content, the hardness of the films increases from 8.5 GPa with x=0.01 to 17.2 GPa with x=0.43.

  • 30.
    Fager, Hanna
    et al.
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Tunnfilmsfysik. Linköpings universitet, Tekniska högskolan.
    Howe, B.M.
    Air Force Research Laboratory, Materials and Manufacturing Directorate, Wright-Patterson AFB, Ohio, USA.
    Greczynski, Grzegorz
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Tunnfilmsfysik. Linköpings universitet, Tekniska högskolan.
    Jensen, Jens
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Tunnfilmsfysik. Linköpings universitet, Tekniska högskolan.
    Mei, A. R. B.
    Frederick Seitz Materials Research Laboratory and Materials Science Department, University of Illinois, USA.
    Lu, Jun
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Tunnfilmsfysik. Linköpings universitet, Tekniska högskolan.
    Greene, J.E.
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Tunnfilmsfysik. Linköpings universitet, Tekniska högskolan.
    Petrov, Ivan
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Tunnfilmsfysik. Linköpings universitet, Tekniska högskolan.
    Hultman, Lars
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Tunnfilmsfysik. Linköpings universitet, Tekniska högskolan.
    Hf-Al-Si-N multilayers deposited by reactive magnetron sputtering from a single Hf0.6Al0.2Si0.2 target using high-flux, low-energy modulated substrate bias: film growth and properties2014Manuskript (preprint) (Övrigt vetenskapligt)
    Abstract [en]

    Hf1−x−yAlxSiyN (0≤x≤0.14, 0≤y≤0.13) single layers and multilayer films are grown on Si(001) at a substrate temperature Ts=250 °C using ultrahigh vacuum magnetically-unbalanced reactive magnetron sputtering from a single Hf0.6Al0.2Si0.2 target in a 5%-N2/Ar atmosphere at a total pressure of 20 mTorr (2.67 Pa). The composition and nanostructure of Hf1−x−yAlxSiyN is controlled during growth by varying the ion energy (Ei) of the ions incident at the film surface, keeping the ion-to-metal flux ratio (Ji/JMe) constant at 8. By sequentially switching Ei between 10 and 40 eV, Hf0.77Al0.10Si0.13N/Hf0.78Al0.14Si0.08N multilayers with bilayer periods Λ = 2-20 nm are grown, in which the Si2p bonding state changes from predominantly Si-Si bonds for films grown at Ei = 10 eV, to mainly Si-N bonds at Ei = 40 eV. Multilayer hardness values increase monotonically from 20 GPa with Λ = 20 nm to 27 GPa with Λ = 2 nm, while multilayer fracture toughness increases with increasing Λ. Multilayers with Λ = 10 nm have the optimized property combination of being bothrelatively hard, H∼24 GPa, and fracture tough.

  • 31.
    Fager, Hanna
    et al.
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Tunnfilmsfysik. Linköpings universitet, Tekniska fakulteten.
    Howe, Brandon M.
    US Air Force, OH 45433 USA.
    Greczynski, Grzegorz
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Tunnfilmsfysik. Linköpings universitet, Tekniska fakulteten.
    Jensen, Jens
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Tunnfilmsfysik. Linköpings universitet, Tekniska fakulteten.
    Mei, A. B.
    University of Illinois, IL 61801 USA; University of Illinois, IL 61801 USA.
    Lu, Jun
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Tunnfilmsfysik. Linköpings universitet, Tekniska fakulteten.
    Hultman, Lars
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Tunnfilmsfysik. Linköpings universitet, Tekniska fakulteten.
    Greene, Joseph E
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Tunnfilmsfysik. Linköpings universitet, Tekniska fakulteten. University of Illinois, IL 61801 USA; University of Illinois, IL 61801 USA.
    Petrov, Ivan
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Tunnfilmsfysik. Linköpings universitet, Tekniska fakulteten. University of Illinois, IL 61801 USA; University of Illinois, IL 61801 USA.
    Novel hard, tough HfAlSiN multilayers, defined by alternating Si bond structure, deposited using modulated high-flux, low-energy ion irradiation of the growing film2015Ingår i: Journal of Vacuum Science & Technology. A. Vacuum, Surfaces, and Films, ISSN 0734-2101, E-ISSN 1520-8559, Vol. 33, nr 5, s. 05E103-1-05E103-9Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Hf1-x-yAlxSiyN (0 less than= x less than= 0.14, 0 less than= y less than= 0.12) single layer and multilayer films are grown on Si(001) at 250 degrees C using ultrahigh vacuum magnetically unbalanced reactive magnetron sputtering from a single Hf0.6Al0.2Si0.2 target in mixed 5%-N-2/Ar atmospheres at a total pressure of 20 mTorr (2.67 Pa). The composition and nanostructure of Hf1-x-yAlxSiyN films are controlled by varying the energy Ei of the ions incident at the film growth surface while maintaining the ion-to-metal flux ratio constant at eight. Switching E-i between 10 and 40 eV allows the growth of Hf0.78Al0.10Si0.12N/Hf0.78Al0.14Si0.08N multilayers with similar layer compositions, but in which the Si bonding state changes from predominantly Si-Si/Si-Hf for films grown with E-i = 10 eV, to primarily Si-N with E-i = 40 eV. Multilayer hardness values, which vary inversely with bilayer period Lambda, range from 20 GPa with Lambda = 20 nm to 27 GPa with Lambda = 2 nm, while fracture toughness increases directly with Lambda. Multilayers with Lambda = 10nm combine relatively high hardness, H similar to 24GPa, with good fracture toughness. (C) 2015 American Vacuum Society.

  • 32.
    Fager, Hanna
    et al.
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Tunnfilmsfysik. Linköpings universitet, Tekniska fakulteten.
    Tengstrand, Olof
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Tunnfilmsfysik. Linköpings universitet, Tekniska fakulteten.
    Lu, Jun
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Tunnfilmsfysik. Linköpings universitet, Tekniska fakulteten.
    Bolz, S.
    CemeCon AG, Germany.
    Mesic, B.
    CemeCon AG, Germany.
    Koelker, W.
    CemeCon AG, Germany.
    Schiffers, Ch.
    CemeCon AG, Germany.
    Lemmer, O.
    CemeCon AG, Germany.
    Greene, Joseph E
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Tunnfilmsfysik. Linköpings universitet, Tekniska fakulteten. University of Illinois, IL 61801 USA; University of Illinois, IL 61801 USA.
    Hultman, Lars
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Tunnfilmsfysik. Linköpings universitet, Tekniska fakulteten.
    Petrov, Ivan
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Tunnfilmsfysik. Linköpings universitet, Tekniska fakulteten. University of Illinois, IL 61801 USA; University of Illinois, IL 61801 USA.
    Greczynski, Grzegorz
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Tunnfilmsfysik. Linköpings universitet, Tekniska fakulteten.
    Low-temperature growth of dense and hard Ti0.41Al0.51Ta0.08N films via hybrid HIPIMS/DC magnetron co-sputtering with synchronized metal-ion irradiation2017Ingår i: Journal of Applied Physics, ISSN 0021-8979, E-ISSN 1089-7550, Vol. 121, nr 17, artikel-id 171902Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Hard Ti1-xAlxN thin films are of importance for metal-cutting applications. The hardness, thermal stability, and oxidation resistance of these coatings can be further enhanced by alloying with TaN. We use a hybrid high-power pulsed and dc magnetron co-sputtering (HIPIMS/DCMS) technique to grow dense and hard Ti0.41Al0.51Ta0.08N alloys without external heating (T-s amp;lt; 150 degrees C). Separate Ti and Al targets operating in the DCMS mode maintain a deposition rate of similar to 50 nm/min, while irradiation of the growing film by heavy Ta+/Ta2+ ions from the HIPIMS-powered Ta target, using dc bias synchronized to the metal-ion-rich part of each HIPIMS pulse, provides effective near-surface atomic mixing resulting in densification. The substrate is maintained at floating potential between the short bias pulses to minimize Ar+ bombardment, which typically leads to high compressive stress. Transmission and scanning electron microscopy analyses reveal dramatic differences in the microstructure of the co-sputtered HIPIMS/DCMS films (Ta-HIPIMS) compared to films with the same composition grown at floating potential with all targets in the DCMS mode (Ta-DCMS). The Ta-DCMS alloy films are only similar to 70% dense due to both inter-and intra-columnar porosity. In contrast, the Ta-HIPIMS layers exhibit no inter-columnar porosity and are essentially fully dense. The mechanical properties of Ta-HIPIMS films are significantly improved with hardness and elastic modulus values of 28.0 and 328 GPa compared to 15.3 and 289 GPa for reference Ta-DCMS films. Published by AIP Publishing.

  • 33.
    Fashandi, Hossein
    et al.
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Tillämpad sensorvetenskap. Linköpings universitet, Tekniska högskolan.
    Andersson, Mike
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Tillämpad sensorvetenskap. Linköpings universitet, Tekniska högskolan.
    Eriksson, Jens
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Tillämpad sensorvetenskap. Linköpings universitet, Tekniska högskolan.
    Lu, Jun
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Tunnfilmsfysik. Linköpings universitet, Tekniska högskolan.
    Smedfors, K.
    School of Information and Communication Technology, KTH, Stockholm, Sweden.
    Zetterling, C. -M
    School of Information and Communication Technology, KTH, Stockholm, Sweden.
    Lloyd Spetz, Anita
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Tillämpad sensorvetenskap. Linköpings universitet, Tekniska högskolan.
    Eklund, Per
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Tunnfilmsfysik. Linköpings universitet, Tekniska högskolan.
    Single-step synthesis process of Ti3SiC2 ohmic contacts on 4H-SiC by sputter-deposition of Ti2015Ingår i: Scripta Materialia, ISSN 1359-6462, E-ISSN 1872-8456, Vol. 99, s. 53-56Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    We report a single-step procedure for growth of ohmic Ti3SiC2 on 4H-SiC by sputter-deposition of Ti at 960 °C, based on the Ti–SiC solid-state reaction during deposition. X-ray diffraction and electron microscopy show the growth of interfacial Ti3SiC2. The as-deposited contacts are ohmic, in contrast to multistep processes with deposition followed by rapid thermal annealing. This procedure also offers the possibility of direct synthesis of oxygen-barrier capping layers before exposure to air, potentially improving contact stability in high-temperature and high-power devices.

  • 34.
    Fashandi, Hossein
    et al.
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Tunnfilmsfysik. Linköpings universitet, Tekniska fakulteten.
    Dahlqvist, Martin
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Tunnfilmsfysik. Linköpings universitet, Tekniska fakulteten.
    Lu, Jun
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Tunnfilmsfysik. Linköpings universitet, Tekniska fakulteten.
    Palisaitis, Justinas
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Tunnfilmsfysik. Linköpings universitet, Tekniska fakulteten.
    Simak, Sergey
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Teoretisk Fysik. Linköpings universitet, Tekniska fakulteten.
    Abrikosov, Igor
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Teoretisk Fysik. Linköpings universitet, Tekniska fakulteten.
    Rosén, Johanna
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Tunnfilmsfysik. Linköpings universitet, Tekniska fakulteten.
    Hultman, Lars
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Tunnfilmsfysik. Linköpings universitet, Tekniska fakulteten.
    Andersson, Mike
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Tillämpad sensorvetenskap. Linköpings universitet, Tekniska fakulteten.
    Lloyd Spetz, Anita
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Tillämpad sensorvetenskap. Linköpings universitet, Tekniska fakulteten.
    Eklund, Per
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Tunnfilmsfysik. Linköpings universitet, Tekniska fakulteten.
    Synthesis of Ti3AuC2, Ti3Au2C2 and Ti3IrC2 by noble metal substitution reaction in Ti3SiC2 for high-temperature-stable Ohmic contacts to SiC2017Ingår i: Nature Materials, ISSN 1476-1122, E-ISSN 1476-4660, Vol. 16, nr 8, s. 814-818Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    The large class of layered ceramics encompasses both van der Waals (vdW) and non-vdW solids. While intercalation of noble metals in vdW solids is known, formation of compounds by incorporation of noble-metal layers in non-vdW layered solids is largely unexplored. Here, we show formation of Ti3AuC2 and Ti3Au2C2 phases with up to 31% lattice swelling by a substitutional solid-state reaction of Au into Ti3SiC2 single-crystal thin films with simultaneous out-diffusion of Si. Ti3IrC2 is subsequently produced by a substitution reaction of Ir for Au in Ti3Au2C2. These phases form Ohmic electrical contacts to SiC and remain stable after 1,000 h of ageing at 600 degrees C in air. The present results, by combined analytical electron microscopy and ab initio calculations, open avenues for processing of noble-metal-containing layered ceramics that have not been synthesized from elemental sources, along with tunable properties such as stable electrical contacts for high-temperature power electronics or gas sensors.

  • 35.
    Fashandi, Hossein
    et al.
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Tunnfilmsfysik. Linköpings universitet, Tekniska fakulteten.
    Lai, Chung-Chuan
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Tunnfilmsfysik. Linköpings universitet, Tekniska fakulteten.
    Dahlqvist, Martin
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Tunnfilmsfysik. Linköpings universitet, Tekniska fakulteten.
    Lu, Jun
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Tunnfilmsfysik. Linköpings universitet, Tekniska fakulteten.
    Rosén, Johanna
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Tunnfilmsfysik. Linköpings universitet, Tekniska fakulteten.
    Hultman, Lars
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Tunnfilmsfysik. Linköpings universitet, Tekniska fakulteten.
    Greczynski, Grzegorz
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Tunnfilmsfysik. Linköpings universitet, Tekniska fakulteten.
    Andersson, Mike
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Tillämpad sensorvetenskap. Linköpings universitet, Tekniska fakulteten.
    Lloyd Spetz, Anita
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Tillämpad sensorvetenskap. Linköpings universitet, Tekniska fakulteten.
    Eklund, Per
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Tunnfilmsfysik. Linköpings universitet, Tekniska fakulteten.
    Ti2Au2C and Ti3Au2C2 formed by solid state reaction of gold with Ti2AlC and Ti3AlC22017Ingår i: Chemical Communications, ISSN 1359-7345, E-ISSN 1364-548X, Vol. 53, nr 69, s. 9554-9557Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Incorporation of layers of noble metals in non-van der Waals layered materials may be used to form novel layered compounds. Recently, we demonstrated a high-temperature-induced exchange process of Au with Si in the layered phase Ti3SiC2, resulting in the formation of Ti3AuC2 and Ti3Au2C2. Here, we generalize this technique showing that Au/Ti2AlC and Au/Ti3AlC2 undergo an exchange reaction at 650 [degree]C to form Ti2Au2C and Ti3Au2C2 and determine their structures by electron microscopy, X-ray diffraction, and ab initio calculations. These results imply that noble-metal-containing layered phases should be possible to synthesize in many systems. The metal to be introduced should be inert to the transition-metal carbide layers, and exhibit negative heat of mixing with the initial A element in a liquid phase or two-phase liquid/solid region at the annealing temperature.

  • 36.
    Frodelius, Jenny
    et al.
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Tunnfilmsfysik. Linköpings universitet, Tekniska högskolan.
    Lu, Jun
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Tunnfilmsfysik. Linköpings universitet, Tekniska högskolan.
    Jensen, Jens
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Tunnfilmsfysik. Linköpings universitet, Tekniska högskolan.
    Paul, Dennis
    Phys Elect USA, USA .
    Hultman, Lars
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Tunnfilmsfysik. Linköpings universitet, Tekniska högskolan.
    Eklund, Per
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Tunnfilmsfysik. Linköpings universitet, Tekniska högskolan.
    Phase stability and initial low-temperature oxidation mechanism of Ti2AlC thin films2013Ingår i: Journal of the European Ceramic Society, ISSN 0955-2219, E-ISSN 1873-619X, Vol. 33, nr 2, s. 375-382Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Ti2AlC thin films deposited onto Al2O3 by magnetron sputtering were used as model for studying the early stages (andlt; 15 min) of relatively low-temperature (500 degrees C) oxidation of Ti2AlC. The well-defined microstructure of these films forms a surface of valleys, hillocks and plateaus comprised of basal-plane-oriented grains with a fraction of nonbasal-plane-oriented grains with out-of-plane orientation of (1 0 (1) over bar 3) and (1 0 (1) over bar 6) as shown by X-ray diffraction and s electron microscopy. During oxidation, Al2O3 clusters and areas of C-containing titania (TiOxCy) are formed on the surface. A mechanism is proposed in which the locations of the Al2O3 clusters are related to the migration of Al atoms diffusing out of Ti2AlC. The Al2O3 is initially formed in valleys or on plateaus where Al atoms have been trapped while TiOxCy forms by in-diffusion of oxygen into the Al-deficient Ti2AlC. At 500 degrees C, the migration of Al atoms is faster than the oxidation kinetics; explaining this microstructure-dependent oxidation mechanism.

  • 37.
    Furlan, Andrej
    et al.
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Tunnfilmsfysik. Linköpings universitet, Tekniska högskolan.
    Jansson, Ulf
    Ångström Laboratory, Uppsala University, Uppsala, Sweden.
    Lu, Jun
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Tunnfilmsfysik. Linköpings universitet, Tekniska högskolan.
    Hultman, Lars
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Tunnfilmsfysik. Linköpings universitet, Tekniska högskolan.
    Magnuson, Martin
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Tunnfilmsfysik. Linköpings universitet, Tekniska högskolan.
    Structure and bonding in amorphous iron carbide thin films2015Ingår i: Journal of Physics: Condensed Matter, ISSN 0953-8984, E-ISSN 1361-648X, Vol. 27, nr 4, s. 045002-Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    We investigate the amorphous structure, chemical bonding, and electrical properties ofmagnetron sputtered Fe1−xCx (0.21 < x < 0.72) thin films. X-ray, electron diffraction andtransmission electron microscopy show that the Fe1−xCx films are amorphousnanocomposites, consisting of a two-phase domain structure with Fe-rich carbidic FeCy , and acarbon-rich matrix. Pair distribution function analysis indicates a close-range order similar tothose of crystalline Fe3C carbides in all films with additional graphene-like structures at highcarbon content (71.8 at% C). From x-ray photoelectron spectroscopy measurements, we findthat the amorphous carbidic phase has a composition of 15–25 at% carbon that slightlyincreases with total carbon content. X-ray absorption spectra exhibit an increasing number ofunoccupied 3d states and a decreasing number of C 2p states as a function of carbon content.These changes signify a systematic redistribution in orbital occupation due to charge-transfereffects at the domain-size-dependent carbide/matrix interfaces. The four-point proberesistivity of the Fe1−xCx films increases exponentially with carbon content from ∼200μcm(x = 0.21) to ∼1200μcm (x = 0.72), and is found to depend on the total carbon contentrather than the composition of the carbide. Our findings open new possibilities for modifyingthe resistivity of amorphous thin film coatings based on transition metal carbides through thecontrol of amorphous domain structures.

  • 38.
    Furlan, Andrej
    et al.
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Tunnfilmsfysik. Linköpings universitet, Tekniska högskolan.
    Lu, Jun
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Tunnfilmsfysik. Linköpings universitet, Tekniska högskolan.
    Hultman, Lars
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Tunnfilmsfysik. Linköpings universitet, Tekniska högskolan.
    Jansson, Ulf
    Uppsala University, Sweden .
    Magnuson, Martin
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Tunnfilmsfysik. Linköpings universitet, Tekniska högskolan.
    Crystallization characteristics and chemical bonding properties of nickel carbide thin film nanocomposites2014Ingår i: Journal of Physics: Condensed Matter, ISSN 0953-8984, E-ISSN 1361-648X, Vol. 26, nr 41, s. 415501-415512Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    The crystal structure and chemical bonding of magnetron-sputtering deposited nickel carbide Ni1−xCx (0.05≤x≤0.62) thin films have been investigated by high-resolution x-ray diffraction, transmission electron microscopy, x-ray photoelectron spectroscopy, Raman spectroscopy, and soft x-ray absorption spectroscopy. By using x-ray as well as electron diffraction, we found carbon-containing hcp-Ni (hcp-NiCy phase), instead of the expected rhombohedral-Ni3C. At low carbon content (4.9 at%), the thin film consists of hcp-NiCy nanocrystallites mixed with a smaller amount of fcc-NiCx. The average grain size is about10–20 nm. With the increase of carbon content to 16.3 at%, the film contains single-phase hcp-NiCy nanocrystallites with expanded lattice parameters. With a further increase of carbon content to 38 at%, and 62 at%, the films transform to x-ray amorphous materials with hcp-NiCy and fcc-NiCx nanodomain structures in an amorphous carbon-rich matrix. Raman spectra of carbon indicate dominant sp2 hybridization, consistent with photoelectron spectra that show a decreasing amount of C–Ni phase with increasing carbon content. The Ni 3d–C 2p hybridization in the hexagonal structure gives rise to the salient double-peak structure in Ni 2p soft x-ray absorption spectra at 16.3 at% that changes with carbon content. We also show thatthe resistivity is not only governed by the amount of carbon, but increases by more than a factor of two when the samples transform from crystalline to amorphous.

  • 39.
    Furlan, Andrej
    et al.
    Uppsala University, Sweden.
    Lu, Jun
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Tunnfilmsfysik. Linköpings universitet, Tekniska högskolan.
    Hultman, Lars
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Tunnfilmsfysik. Linköpings universitet, Tekniska högskolan.
    Jonsson, Ulf
    Uppsala University, Sweden.
    Control of crystallinity in sputtered Cr–Ti–C films2013Ingår i: Acta Materialia, ISSN 1359-6454, E-ISSN 1873-2453, Vol. 61, nr 17, s. 6352-6361Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    The influence of Ti content on crystallinity and bonding of Cr–Ti–C thin films deposited by magnetron sputtering have been studied by X-ray diffraction, X-ray photoelectron spectroscopy, transmission electron microscopy and Raman spectroscopy. Our results show that binary Cr–C films without Ti exhibit an amorphous structure with two non-crystalline components; amorphous CrCx and amorphous C (a-C). The addition of 10–20 at.% Ti leads to the crystallization of the amorphous CrCx and the formation of a metastable cubic (Cr1−xTix)Cy phase. The observation was explained based on the tendency of the 3d transition metals to form crystalline carbide films. The mechanical properties of the films determined by nanoindentation and microindentation were found to be strongly dependent on the film composition in terms of hardness, elasticity modulus, hardness/elasticity ratio and crack development.

  • 40.
    Gao, Xindong
    et al.
    Solid-State Electronics, The Ångström Laboratory, Uppsala University, Uppsala .
    Andersson, Joakim
    Solid-State Electronics, The Ångström Laboratory, Uppsala University, Uppsala .
    Kubart, Tomas
    Solid-State Electronics, The Ångström Laboratory, Uppsala University, Uppsala .
    Nyberg, Tomas
    Solid-State Electronics, The Ångström Laboratory, Uppsala University, Uppsala .
    Smith, Ulf
    Solid-State Electronics, The Ångström Laboratory, Uppsala University, Uppsala .
    Lu, Jun
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Tunnfilmsfysik. Linköpings universitet, Tekniska högskolan.
    Hultman, Lars
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Tunnfilmsfysik. Linköpings universitet, Tekniska högskolan.
    Kellock, Andrew J
    IBM Almaden Research Center, San Jose, California, USA .
    Zhang, Zhen
    IBM T.J. Watson Research Center, Yorktown Heights, New York , USA.
    Lavoie, Christian
    IBM T.J. Watson Research Center, Yorktown Heights, New York , USA.
    Zhang, Shi-Li
    Solid-State Electronics, The Ångström Laboratory, Uppsala University, Uppsala .
    Epitaxy of Ultrathin NiSi2 Films with Predetermined Thickness2011Ingår i: ELECTROCHEMICAL AND SOLID STATE LETTERS, ISSN 1099-0062, Vol. 14, nr 7, s. H268-H270Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    This letter presents a proof-of-concept process for tunable, self-limiting growth of ultrathin epitaxial NiSi2 films on Si (100). The process starts with metal sputter-deposition, followed by wet etching and then silicidation. By ionizing a fraction of the sputtered Ni atoms and biasing the Si substrate, the amount of Ni atoms incorporated in the substrate after wet etching can be controlled. As a result, the thickness of the NiSi2 films is increased from 4.7 to 7.2 nm by changing the nominal substrate bias from 0 to 600 V. The NiSi2 films are characterized by a specific resistivity around 50 mu Omega cm.

  • 41.
    Gharavi, Mohammad Amin
    et al.
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Tunnfilmsfysik. Linköpings universitet, Tekniska fakulteten.
    Greczynski, Grzegorz
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Tunnfilmsfysik. Linköpings universitet, Tekniska fakulteten.
    Eriksson, Fredrik
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Tunnfilmsfysik. Linköpings universitet, Tekniska fakulteten.
    Lu, Jun
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Tunnfilmsfysik. Linköpings universitet, Tekniska fakulteten.
    Balke, B.
    Univ Stuttgart, Germany.
    Fournier, D.
    Sorbonne Univ, France.
    Le Febvrier, Arnaud
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Tunnfilmsfysik. Linköpings universitet, Tekniska fakulteten.
    Pallier, Camille
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Tunnfilmsfysik. Linköpings universitet, Tekniska fakulteten.
    Eklund, Per
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Tunnfilmsfysik. Linköpings universitet, Tekniska fakulteten.
    Synthesis and characterization of single-phase epitaxial Cr2N thin films by reactive magnetron sputtering2019Ingår i: Journal of Materials Science, ISSN 0022-2461, E-ISSN 1573-4803, Vol. 54, nr 2, s. 1434-1442Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Cr2N is commonly found as a minority phase or inclusion in stainless steel, CrN-based hard coatings, etc. However, studies on phase-pure material for characterization of fundamental properties are limited. Here, Cr2N thin films were deposited by reactive magnetron sputtering onto (0001) sapphire substrates. X-ray diffraction and pole figure texture analysis show Cr2N (0001) epitaxial growth. Scanning electron microscopy imaging shows a smooth surface, while transmission electron microscopy and X-ray reflectivity show a uniform and dense film with a density of 6.6gcm(-3), which is comparable to theoretical bulk values. Annealing the films in air at 400 degrees C for 96h shows little signs of oxidation. Nano-indentation shows an elastic-plastic behavior with H=18.9GPa and E-r=265GPa. The moderate thermal conductivity is 12Wm(-1)K(-1), and the electrical resistivity is 70cm. This combination of properties means that Cr2N may be of interest in applications such as protective coatings, diffusion barriers, capping layers and contact materials.

  • 42.
    Gharavi, Mohammad Amin
    et al.
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Tunnfilmsfysik. Linköpings universitet, Tekniska fakulteten.
    Kerdsongpanya, Sit
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Tunnfilmsfysik. Linköpings universitet, Tekniska fakulteten. Rensselaer Polytech Inst, NY 12180 USA.
    Schmidt, Susann
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Tunnfilmsfysik. Linköpings universitet, Tekniska fakulteten.
    Eriksson, Fredrik
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Tunnfilmsfysik. Linköpings universitet, Tekniska fakulteten.
    Nong, N. V
    Tech Univ Denmark, Denmark.
    Lu, Jun
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Tunnfilmsfysik. Linköpings universitet, Tekniska fakulteten.
    Balke, B.
    Johannes Gutenberg Univ Mainz, Germany.
    Fournier, D.
    UPMC Univ Paris 06, France.
    Belliard, L.
    UPMC Univ Paris 06, France.
    Le Febvrier, Arnaud
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Tunnfilmsfysik. Linköpings universitet, Tekniska fakulteten.
    Pallier, Camille
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Tunnfilmsfysik. Linköpings universitet, Tekniska fakulteten.
    Eklund, Per
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Tunnfilmsfysik. Linköpings universitet, Tekniska fakulteten.
    Microstructure and thermoelectric properties of CrN and CrN/Cr2N thin films2018Ingår i: Journal of Physics D: Applied Physics, ISSN 0022-3727, E-ISSN 1361-6463, Vol. 51, nr 35, artikel-id 355302Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    CrN thin films with an N/Cr ratio of 95% were deposited by reactive magnetron sputtering onto (0001) sapphire substrates. X-ray diffraction and pole figure texture analysis show CrN (111) epitaxial growth in a twin domain fashion. By changing the nitrogen versus argon gas flow mixture and the deposition temperature, thin films with different surface morphologies ranging from grainy rough textures to flat and smooth films were prepared. These parameters can also affect the CrN(x )system, with the film compound changing between semiconducting CrN and metallic Cr2N through the regulation of the nitrogen content of the gas flow and the deposition temperature at a constant deposition pressure. Thermoelectric measurements (electrical resistivity and Seebeck coefficient), scanning electron microscopy, and transmission electron microscopy imaging confirm the changing electrical resistivity between 0.75 and 300 m omega cm, the changing Seebeck coefficient values between 140 and 230 mu VK-1, and the differences in surface morphology and microstructure as higher temperatures result in lower electrical resistivity while gas flow mixtures with higher nitrogen content result in single phase cubic CrN.

  • 43.
    Goyenola, Cecilia
    et al.
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Tunnfilmsfysik. Linköpings universitet, Tekniska fakulteten.
    Lai, Chung-Chuan
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Tunnfilmsfysik. Linköpings universitet, Tekniska fakulteten.
    Näslund, Lars-Åke
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Tunnfilmsfysik. Linköpings universitet, Tekniska fakulteten.
    Lu, Jun
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Tunnfilmsfysik. Linköpings universitet, Tekniska fakulteten.
    Högberg, Hans
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Tunnfilmsfysik. Linköpings universitet, Tekniska fakulteten.
    Hultman, Lars
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Tunnfilmsfysik. Linköpings universitet, Tekniska fakulteten.
    Rosén, Johanna
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Tunnfilmsfysik. Linköpings universitet, Tekniska fakulteten.
    Gueorguiev, Gueorgui Kostov
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Tunnfilmsfysik. Linköpings universitet, Tekniska fakulteten.
    Theoretical prediction and synthesis of CSxFy thin films2016Ingår i: The Journal of Physical Chemistry C, ISSN 1932-7447, E-ISSN 1932-7455, Vol. 120, nr 17, s. 9527-9534Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    A new carbon-based compound: CSxFy was addressed by density functional theory calculations and synthesized by reactive magnetron sputtering. Geometry optimizations and energy calculations were performed on graphene-like model systems containing sulfur and fluorine atoms. It is shown that [S+F] concentrations in the range of 0−10 at.%, structural ordered characteristics similar to graphene pieces containing ring defects are energetically feasible. The modeling predicts that CSxFy thin films with graphite and fullerene-like characteristics may be obtained for the mentioned concentration range. Accordingly, thin films were synthesized from a graphite solid target and sulfur hexafluoride as reactive gas. In agreement with the theoretical prediction, transmission electron microscopy characterization and selected area electron diffraction confirmed the presence of small ordered clusters with graphitic features in a sample containing 0.4 at.% of S and 3.4 at.% of F.

  • 44.
    Greczynski, Grzegorz
    et al.
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Tunnfilmsfysik. Linköpings universitet, Tekniska högskolan.
    Lu, Jun
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Tunnfilmsfysik. Linköpings universitet, Filosofiska fakulteten.
    Bolz, Stephan
    CemeCon AG, Wűrselen, Germany.
    Koelker, Werner
    CemeCon AG, Wűrselen, Germany.
    Schiffers, Christoph
    CemeCon AG, Wűrselen, Germany.
    Lemmer, Oliver
    CemeCon AG, Wűrselen, Germany.
    Petrov, Ivan
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Tunnfilmsfysik. Linköpings universitet, Tekniska högskolan. University of Illinois, Urbana, USA .
    Greene, Joseph E
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Tunnfilmsfysik. Linköpings universitet, Tekniska högskolan. University of Illinois, Urbana, USA .
    Hultman, Lars
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Tunnfilmsfysik. Linköpings universitet, Tekniska högskolan.
    Novel strategy for low-temperature, high-rate growth of dense, hard, and stress-free refractory ceramic thin films2014Ingår i: Journal of Vacuum Science & Technology. A. Vacuum, Surfaces, and Films, ISSN 0734-2101, E-ISSN 1520-8559, Vol. 32, nr 4, s. 041515-Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Growth of fully dense refractory thin films by means of physical vapor deposition (PVD) requires elevated temperatures T-s to ensure sufficient adatom mobilities. Films grown with no external heating are underdense, as demonstrated by the open voids visible in cross-sectional transmission electron microscopy images and by x-ray reflectivity results; thus, the layers exhibit low nanoindentation hardness and elastic modulus values. Ion bombardment of the growing film surface is often used to enhance densification; however, the required ion energies typically extract a steep price in the form of residual rare-gas-ion-induced compressive stress. Here, the authors propose a PVD strategy for the growth of dense, hard, and stress-free refractory thin films at low temperatures; that is, with no external heating. The authors use TiN as a model ceramic materials system and employ hybrid high-power pulsed and dc magnetron co-sputtering (HIPIMS and DCMS) in Ar/N-2 mixtures to grow dilute Ti1-xTaxN alloys on Si(001) substrates. The Ta target driven by HIPIMS serves as a pulsed source of energetic Ta+/Ta2+ metal-ions, characterized by in-situ mass and energy spectroscopy, while the Ti target operates in DCMS mode (Ta-HIPIMS/Ti-DCMS) providing a continuous flux of metal atoms to sustain a high deposition rate. Substrate bias V-s is applied in synchronous with the Ta-ion portion of each HIPIMS pulse in order to provide film densification by heavy-ion irradiation (m(Ta) = 180.95 amu versus m(Ti) = 47.88 amu) while minimizing Ar+ bombardment and subsequent trapping in interstitial sites. Since Ta is a film constituent, primarily residing on cation sublattice sites, film stress remains low. Dense Ti0.92Ta0.08N alloy films, 1.8 mu m thick, grown with T-s less than= 120 degrees C (due to plasma heating) and synchronized bias, V-s = 160 V, exhibit nanoindentation hardness H = 25.9 GPa and elastic modulus E = 497 GPa compared to 13.8 and 318 GPa for underdense Ti-HIPIMS/Ti-DCMS TiN reference layers (T-s less than 120 degrees C) grown with the same V-s, and 7.8 and 248 GPa for DCMS TiN films grown with no applied bias (T-s less than 120 degrees C). Ti0.92Ta0.08N residual stress is low, sigma = -0.7 GPa, and essentially equal to that of Ti-HIPIMS/Ti-DCMS TiN films grown with the same substrate bias.

  • 45.
    Greczynski, Grzegorz
    et al.
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Tunnfilmsfysik. Linköpings universitet, Tekniska högskolan.
    Lu, Jun
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Tunnfilmsfysik. Linköpings universitet, Tekniska högskolan.
    Jensen, Jens
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Tunnfilmsfysik. Linköpings universitet, Tekniska högskolan.
    Bolz, S.
    CemeCon AG, Germany.
    Koelker, W.
    CemeCon AG, Germany.
    Schiffers, Ch.
    CemeCon AG, Germany.
    Lemmer, O.
    CemeCon AG, Germany.
    Greene, Joseph E
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Tunnfilmsfysik. Linköpings universitet, Tekniska högskolan. University of Illinois, IL 61801 USA; University of Illinois, IL 61801 USA.
    Hultman, Lars
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Tunnfilmsfysik. Linköpings universitet, Tekniska högskolan.
    A review of metal-ion-flux-controlled growth of metastable TiAlN by HIPIMS/DCMS co-sputtering2014Ingår i: Surface & Coatings Technology, ISSN 0257-8972, E-ISSN 1879-3347, Vol. 257, s. 15-25Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    We review results on the growth of metastable Ti1-xAlxN alloy films by hybrid high-power pulsed and dc magnetron co-sputtering (HIPIMS/DCMS) using the time domain to apply substrate bias either in synchronous with the entire HIPIMS pulse or just the metal-rich portion of the pulse in mixed Ar/N-2 discharges. Depending upon which elemental target, Ti or Al, is powered by HIPIMS, distinctly different film-growth kinetic pathways are observed due to charge and mass differences in the metal-ion fluxes incident at the growth surface. Al+ ion irradiation during Al-HIPIMS/Ti-DCMS at 500 degrees C, with a negative substrate bias V-s = 60 V synchronized to the HIPIMS pulse (thus suppressing Ar+ ion irradiation due to DCMS), leads to single-phase NaCl-structure Ti1-xAlxN films (x less than= 0.60) with high hardness (greater than30 GPa with x greater than 0.55) and low stress (0.2-0.8 GPa compressive). Ar+ ion bombardment can be further suppressed in favor of predominantly Al+ ion irradiation by synchronizing the substrate bias to only the metal-ion-rich portion of the Al-HIPIMS pulse. In distinct contrast Ti-HIPIMS/Al-DCMSTi1-xAlxN layers grown with Ti+/Ti2+ metal ion irradiation and the same HIPIMS-synchronized V-s value, are two-phase mixtures, NaCl-structure Ti1-xAlxN plus wurtzite AlN, exhibiting low hardness (similar or equal to 18 GPa) with high compressive stresses, up to -3.5 GPa. In both cases, film properties are controlled by the average metal-ion momentum per deposited atom less thanp(d)greater than transferred to the film surface. During Ti-HIPIMS, the growing film is subjected to an intense flux of doubly-ionized Ti2+, while Al2+ irradiation is insignificant during Al-HIPIMS. This asymmetry is decisive since the critical less thanp(d)greater than limit for precipitation of w-AlN, 135 [eV-amu](1/2), is easily exceeded during Ti-HIPIMS, even with no intentional bias. The high Ti2+ ion flux is primarily due to the second ionization potential (IP2) of Ti being lower than the first IP (IP1) of Ar. New results involving the HIPIMS growth of metastable Ti1-xAlxN alloy films from segmented TiAl targets are consistent with the above conclusions.

  • 46.
    Greczynski, Grzegorz
    et al.
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Tunnfilmsfysik. Linköpings universitet, Tekniska högskolan.
    Lu, Jun
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Tunnfilmsfysik. Linköpings universitet, Tekniska högskolan.
    Jensen, Jens
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Tunnfilmsfysik. Linköpings universitet, Tekniska högskolan.
    Petrov, Ivan
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Tunnfilmsfysik. Linköpings universitet, Tekniska högskolan.
    Greene, Joseph E
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Tunnfilmsfysik. Linköpings universitet, Tekniska högskolan.
    Bolz, S.
    CemeCon AG, Germany .
    Koelker, W.
    CemeCon AG, Germany .
    Schiffers, Ch.
    CemeCon AG, Germany .
    Lemmer, O.
    CemeCon AG, Germany .
    Hultman, Lars
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Tunnfilmsfysik. Linköpings universitet, Tekniska högskolan.
    Strain-free, single-phase metastable Ti0.38Al0.62N alloys with high hardness: metal-ion energy vs. momentum effects during film growth by hybrid high-power pulsed/dc magnetron cosputtering2014Ingår i: Thin Solid Films, ISSN 0040-6090, E-ISSN 1879-2731, Vol. 556, s. 87-98Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    A hybrid deposition process consisting of reactive high-power pulsed and dc magnetron cosputtering (HIPIMS and DCMS) from Ti and Al targets is used to grow Ti1-xAlxN alloys, with x similar to 0.6, on Si(001) at 500 degrees C. Two series of films are deposited in which the energy and momentum of metal ions incident at the growing film are individually varied. In both sets of experiments, a negative bias V-s ranging from 20 to 280 V is applied to the substrate in synchronous, as determined by in-situ mass spectrometry, with the metal-ion-rich part of the HIPIMS pulse. Ion momentum is varied by switching the HIPIMS and dc power supplies to change the mass m and average charge of the primary metal ion. Al-HIPIMS/Ti-DCMS layers grown under Al+ (m(Al) = 26.98 amu) bombardment with 20 less than= V-s less than= 160 V are single-phase NaCl-structure alloys, while films deposited with V-s greater than 160 V are two-phase, cubic plus wurtzite. The corresponding critical average metal-ion momentum transfer per deposited atom for phase separation is less than p(d)*greater than greater than= 135 [eV-amu](1/2). In distinct contrast, layers deposited in the Ti-HIPIMS/Al-DCMS configuration with Ti+/Ti2+ (m(Ti) = 47.88 amu) ion irradiation are two-phase even with the lowest bias, V-s = 20 V, for which less than p(d)*greater than greater than 135 [eV-amu](1/2). Precipitation of wurtzite-structure AlN is primarily determined by the average metal-ion momentum transfer to the growing film, rather than by the deposited metal-ion energy. Ti-HIPIMS/Al-DCMS layers grown with V-s= 20 V are two-phase with compressive stress sigma= -2 GPa which increases to -6.2 GPa at V-s= 120 V; hardness H values range from 17.5 to 27 GPa and are directly correlated with sigma. However, for Al-HIPIMS/Ti-DCMS, the relatively low mass and single charge of the Al+ ion permits tuning properties of metastable cubic Ti0.38Al0.62 N by adjusting V-s to vary, for example, the hardness from 12 to 31 GPa while maintaining sigma similar to 0.

  • 47.
    Greczynski, Grzegorz
    et al.
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Tunnfilmsfysik. Linköpings universitet, Tekniska högskolan.
    Lu, Jun
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Tunnfilmsfysik. Linköpings universitet, Tekniska högskolan.
    Jensen, Jens
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Tunnfilmsfysik. Linköpings universitet, Tekniska högskolan.
    Petrov, Ivan
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Tunnfilmsfysik. Linköpings universitet, Tekniska högskolan.
    Greene, Joseph E.
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Tunnfilmsfysik. Linköpings universitet, Tekniska högskolan.
    Bolz, Stephan
    CemeCon AG, Germany .
    Koelker, Werner
    CemeCon AG, Germany .
    Schiffers, Christoph
    CemeCon AG, Germany .
    Lemmer, Oliver
    CemeCon AG, Germany .
    Hultman, Lars
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Tunnfilmsfysik. Linköpings universitet, Tekniska högskolan.
    Metal versus rare-gas ion irradiation during Ti1-xAlxN film growth by hybrid high power pulsed magnetron/dc magnetron co-sputtering using synchronized pulsed substrate bias2012Ingår i: Journal of Vacuum Science & Technology. A. Vacuum, Surfaces, and Films, ISSN 0734-2101, E-ISSN 1520-8559, Vol. 30, nr 6Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Metastable NaCl-structure Ti1-xAlxN is employed as a model system to probe the effects of metal versus rare-gas ion irradiation during film growth using reactive high-power pulsed magnetron sputtering (HIPIMS) of Al and dc magnetron sputtering of Ti. The alloy film composition is chosen to be x = 0.61, near the kinetic solubility limit at the growth temperature of 500 degrees C. Three sets of experiments are carried out: a -60V substrate bias is applied either continuously, in synchronous with the full HIPIMS pulse, or in synchronous only with the metal-rich-plasma portion of the HIPIMS pulse. Alloy films grown under continuous dc bias exhibit a thickness-invariant small-grain, two-phase nanostructure (wurtzite AlN and cubic Ti1-xAlxN) with random orientation, due primarily to intense Ar+ irradiation leading to Ar incorporation (0.2 at. %), high compressive stress (-4.6 GPa), and material loss by resputtering. Synchronizing the bias with the full HIPIMS pulse results in films that exhibit much lower stress levels (-1.8GPa) with no measureable Ar incorporation, larger grains elongated in the growth direction, a very small volume fraction of wurtzite AlN, and random orientation. By synchronizing the bias with the metal-plasma phase of the HIPIMS pulses, energetic Ar+ ion bombardment is greatly reduced in favor of irradiation predominantly by Al+ ions. The resulting films are single phase with a dense competitive columnar structure, strong 111 orientation, no measureable trapped Ar concentration, and even lower stress (-0.9 GPa). Thus, switching from Ar+ to Al+ bombardment, while maintaining the same integrated incident ion/metal ratio, eliminates phase separation, minimizes renucleation during growth, and reduces the high concentration of residual point defects, which give rise to compressive stress.

  • 48.
    Greczynski, Grzegorz
    et al.
    Linköpings universitet, Institutionen för fysik, kemi och biologi. Linköpings universitet, Tekniska högskolan.
    Lu, Jun
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Tunnfilmsfysik. Linköpings universitet, Tekniska högskolan.
    Johansson, M
    Seco Tools AB.
    Jensen, Jens
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Tunnfilmsfysik. Linköpings universitet, Tekniska högskolan.
    Petrov, Ivan
    Linköpings universitet, Institutionen för fysik, kemi och biologi. Linköpings universitet, Tekniska högskolan.
    Greene, Joseph E
    Linköpings universitet, Institutionen för fysik, kemi och biologi. Linköpings universitet, Tekniska högskolan.
    Hultman, Lars
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Tunnfilmsfysik. Linköpings universitet, Tekniska högskolan.
    Selection of metal ion irradiation for controlling Ti1-xAlxN alloy growth via hybrid HIPIMS/magnetron co-sputtering2012Ingår i: Vacuum, ISSN 0042-207X, E-ISSN 1879-2715, Vol. 86, nr 8, s. 1036-1040Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    We demonstrate, for the first time, the growth of metastable single-phase NaCl-structure high-AlN-content Ti1-xAlxN alloys (x andlt;= 0.64) which simultaneously possess high hardness and low residual stress. The films are grown using a hybrid approach combining high-power pulsed magnetron (HPPMS/HIPIMS) and dc magnetron sputtering of opposing metal targets. With HIPIMS applied to the Al target, Aln+ ion irradiation (dominated by Aln+) of the growing film results in alloys 0.55 andlt;= x andlt;= 0.60 which exhibit hardness H similar to 30 GPa and low stress sigma = 0.2-0.7 GPa, tensile. In sharp contrast, films with corresponding AlN concentrations grown with HIPIMS applied to the Ti target, giving rise to Tin+ ion irradiation (with a significant Ti2+ component), are two-phase - cubic (Ti,Al)N and hexagonal AlN - with low hardness, H = 18-19 GPa, and high compressive stress ranging up to 2.7 GPa. Annealing alloys grown with HIPIMS applied to the Al target results in age hardening due to spinodal decomposition; the hardness of Ti0.41Al0.59N increases from 30 to 33 GPa following a 900 degrees C anneal.

  • 49.
    Greczynski, Grzegorz
    et al.
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Tunnfilmsfysik. Linköpings universitet, Tekniska högskolan.
    Lu, Jun
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Tunnfilmsfysik. Linköpings universitet, Tekniska högskolan.
    Johansson, M.P.
    Sweden Seco Tools AB, Sweden .
    Jensen, Jens
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Tunnfilmsfysik. Linköpings universitet, Tekniska högskolan.
    Petrov, Ivan
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Tunnfilmsfysik. Linköpings universitet, Tekniska högskolan.
    Greene, Joseph E
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Tunnfilmsfysik. Linköpings universitet, Tekniska högskolan.
    Hultman, Lars
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Tunnfilmsfysik. Linköpings universitet, Tekniska högskolan.
    Role of Tin+ and Aln+ ion irradiation (n=1, 2) during Ti1-xAlxN alloy film growth in a hybrid HIPIMS/magnetron mode2012Ingår i: Surface & Coatings Technology, ISSN 0257-8972, E-ISSN 1879-3347, Vol. 206, nr 19-20, s. 4202-4211Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Metastable Ti1-xAlxN (0.4 less than= x less than= 0.76) films are grown using a hybrid approach in which high-power pulsed magnetron sputtering (HIPIMS) is combined with dc magnetron sputtering (DCMS). Elemental Al and Ti metal targets are co-sputtered with one operated in HIPIMS mode and the other target in DCMS; the positions of the targets are then switched for the next set of experiments. In both cases, the AlN concentration in the co-sputtered films, deposited at T-s = 500 degrees C with R = 1.5-5.3 angstrom/s, is controlled by adjusting the average DCMS target power. Resulting films are analyzed by X-ray diffraction, scanning electron microscopy, transmission electron microscopy, atomic force microscopy, elastic recoil detection analysis, and nanoindentation. Mass spectroscopy is used to determine ion energy distribution functions at the substrate. The distinctly different flux distributions obtained from targets driven in HIPIMS vs. DCMS modes allow the effects of Aln+ and Tin+ (n = 1, 2) ion irradiation on film growth kinetics, and resulting properties, to be investigated separately. Bombardment with Aln+ ions (primarily Al+ in the Al-HIPIMS/Ti-DCMS configuration) during film growth leads to NaCl-structure Ti1-xAlxN (0.53 less than= x less than= 0.60) films which exhibit high hardness (greater than30 GPa) with low stress (0.2-0.7 GPa tensile). In contrast, films with corresponding AlN concentrations grown under Tin+ metal ion irradiation (with a significant Ti2+ component) in the Ti-HIPIMS/Al-DCMS mode have much lower hardness, 18-19 GPa, and high compressive stress ranging up to 2.7 GPa. The surprisingly large variation in mechanical properties results from the fact that the kinetic AlN solubility limit x(max) in Ti1-xAlxN depends strongly on, in addition to T-s and R, the target power configuration during growth and hence the composition of the ion flux. AlN with x(max)similar to 64 mol% can be accommodated in the NaCl structure under Aln+ ion flux, compared with similar to 40 mol% for growth with Tin+ flux. The strong asymmetry in film growth reaction paths is due primarily to the fact that the doubly-ionized metal ion flux is approximately two orders of magnitude higher from the Ti target, than from Al, powered with HIPIMS. This asymmetry becomes decisive upon application of a moderate substrate bias voltage, -60 V, applied synchronously with HIPIMS pulses, during growth.

  • 50.
    Greczynski, Grzegorz
    et al.
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Tunnfilmsfysik. Linköpings universitet, Tekniska fakulteten.
    Lu, Jun
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Tunnfilmsfysik. Linköpings universitet, Tekniska fakulteten.
    Tengstrand, Olof
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Tunnfilmsfysik. Linköpings universitet, Tekniska fakulteten.
    Petrov, Ivan
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Tunnfilmsfysik. Linköpings universitet, Tekniska fakulteten. Materials Science and Physics Departments, Frederick Seitz Materials Research Laboratory, University of of Illinois, Urbana, IL, United States.
    Greene, Joseph E.
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Tunnfilmsfysik. Linköpings universitet, Tekniska fakulteten. Materials Science and Physics Departments, Frederick Seitz Materials Research Laboratory, University of of Illinois, Urbana, IL, United States.
    Hultman, Lars
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Tunnfilmsfysik. Linköpings universitet, Tekniska fakulteten.
    Nitrogen-doped bcc-Cr films: Combining ceramic hardness with metallic toughness and conductivity2016Ingår i: Scripta Materialia, ISSN 1359-6462, E-ISSN 1872-8456, Vol. 122, s. 40-44Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    We report the first results on nanostructured N-doped bcc-Cr films exhibiting the unique combination of ceramic hardness with metallic toughness and electrical conductivity at unexpectedly low N concentrations, ~ 5 at.%. The Cr:N films are deposited at 200 C in N2/Ar mixtures by high-power pulsed magnetron sputtering using tunable time-domain control of Cr+ and Cr2+ ion fluxes incident at the film growth surface. Subplanted N atoms impede annealing of metal-ion induced point defects and hinder bcc-Cr grain growth, resulting in a material with a nearly isotropic nanostructure and atomically smooth surface, rather than typical Cr:N solid solutions consisting of faceted microcolumns. © 2016 Elsevier Ltd.

1234 1 - 50 av 177
RefereraExporteraLänk till träfflistan
Permanent länk
Referera
Referensformat
  • apa
  • harvard1
  • ieee
  • modern-language-association-8th-edition
  • vancouver
  • oxford
  • Annat format
Fler format
Språk
  • de-DE
  • en-GB
  • en-US
  • fi-FI
  • nn-NO
  • nn-NB
  • sv-SE
  • Annat språk
Fler språk
Utmatningsformat
  • html
  • text
  • asciidoc
  • rtf