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Emmerlich, Jens
Publications (10 of 25) Show all publications
Emmerlich, J., Gassner, G., Eklund, P., Högberg, H. & Hultman, L. (2008). Micro and macroscale tribological behavior of epitaxial Ti3SiC2 thin films. Wear, 264(11-12), 914-919
Open this publication in new window or tab >>Micro and macroscale tribological behavior of epitaxial Ti3SiC2 thin films
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2008 (English)In: Wear, ISSN 0043-1648, E-ISSN 1873-2577, Vol. 264, no 11-12, p. 914-919Article in journal (Refereed) Published
Abstract [en]

Ti3SiC2(0 0 0 1) thin films prepared by magnetron sputtering were investigated for their response to tribomechanical strain induced during ball-on-disk experiments with 6 mm alumina balls and scratch tests with a 1 μm cono-spherical diamond tip. Normal loads of 100 μN to 0.24 N were applied resulting in a friction coefficient of 0.1 for the low loads. With higher applied normal loads, the friction coefficient increased up to 0.8. Analysis of the wear tracks using atomic force microscopy, scanning electron microscopy, and Raman spectroscopy revealed excessive debris resulting in third-body abrasion and fast wear. The formation of the debris can be explained by the generation of subsurface delamination cracks on basal planes. Subsequent kink formation obstructs the ball movement which results in the removal of the kinked film parts.

Place, publisher, year, edition, pages
Amsterdam, Netherlands: Elsevier, 2008
National Category
Natural Sciences
Identifiers
urn:nbn:se:liu:diva-39728 (URN)10.1016/j.wear.2007.06.013 (DOI)000254766900002 ()50916 (Local ID)50916 (Archive number)50916 (OAI)
Available from: 2009-10-10 Created: 2009-10-10 Last updated: 2017-12-13Bibliographically approved
Scabarozi, T., Eklund, P., Emmerlich, J., Högberg, H., Meehan, T., Finkel, P., . . . Lofland, S. (2008). Weak electronic anisotropy in the layered nanolaminate Ti 2 GeC. Solid State Communications, 146(11-12), 498-501
Open this publication in new window or tab >>Weak electronic anisotropy in the layered nanolaminate Ti 2 GeC
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2008 (English)In: Solid State Communications, ISSN 0038-1098, E-ISSN 1879-2766, Vol. 146, no 11-12, p. 498-501Article in journal (Refereed) Published
Abstract [en]

We have investigated the anisotropy in electronic transport of the layered ternary Ti2GeC by comparing the results of measurements on c-axis oriented epitaxial thin-film and polycrystalline bulk samples. The electrical conductivities, Hall coefficients, and magnetoresistances were analyzed within a multi-band framework. An adequate description of the magnetotransport data on the film with the highest mobility required the use of the explicit field-dependent conductivity tensor with three conduction bands. The analysis indicated that n ˜ p, although with n ˜ 3.5 × 1027 m- 3. The ratio of the a- to c-axis conductivities is small and contrary to theoretical predictions. © 2008 Elsevier Ltd. All rights reserved.

Keywords
A. MAX phase, B. Thin films, D. Anisotropy, D. Electronic transport
National Category
Engineering and Technology
Identifiers
urn:nbn:se:liu:diva-45966 (URN)10.1016/j.ssc.2008.03.026 (DOI)
Available from: 2009-10-11 Created: 2009-10-11 Last updated: 2017-12-13
Emmerlich, J., Eklund, P., Rittrich, D., Högberg, H. & Hultman, L. (2007). Electrical resistivity of Tin+1ACn (A = Si, Ge, Sn, n = 1–3) thin films. Journal of Materials Research, 22(8), 2279-2287
Open this publication in new window or tab >>Electrical resistivity of Tin+1ACn (A = Si, Ge, Sn, n = 1–3) thin films
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2007 (English)In: Journal of Materials Research, ISSN 0884-2914, E-ISSN 2044-5326, Vol. 22, no 8, p. 2279-2287Article in journal (Refereed) Published
Abstract [en]

We have investigated the electrical resistivity of (0001)-oriented Tin+1ACn (A = Si, Ge, Sn, n = 1–3) thin films deposited by magnetron sputtering onto Al2O3(0001) substrates at temperatures ranging from 500 to 950 °C. Four-point-probe measurements show that all films are good conductors with resistivity values of ∼21–51 μΩ cm for Ti–Si–C films, ∼15–50 μΩ cm for Ti–Ge–C films, and ∼46 μΩ cm for Ti2SnC. We find a general trend of decreasing resistivity with decreasing n for the Ti–Si–C and Ti–Ge–C systems due to the increased metallicity obtained with increasing density of A-element layers. We also show that crystalline quality and competitive growth of impurity phases affect the measured resistivity values. The effect of a given impurity phase largely depends on its location in the sample. Specifically, a TiCx layer in the center of the film constricts the current flow and results in an increased measured resistivity value. However, TiCx transition or seed layers at the substrate–film interface as well as surface segregation of Ge and Ti5Ge3Cx (for Ti–Ge–C) have only little effect on the measured resistivity values. For the Ti–Sn–C system, the resistivity is mainly influenced by the segregation of metallic Sn, yielding a wide spread in the measured values ranging from 20–46 μΩ cm, in the order of increased film purity.

National Category
Natural Sciences
Identifiers
urn:nbn:se:liu:diva-14476 (URN)10.1557/jmr.2007.0284 (DOI)
Available from: 2007-05-14 Created: 2007-05-14 Last updated: 2017-12-13
Eklund, P., Murugaiah, A., Emmerlich, J., Czigany, Z., Frodelius, J., Barsoum, M. W., . . . Hultman, L. (2007). Homoepitaxial growth of Ti-Si-C MAX-phase thin films on bulk Ti3SiC2 substrates. Journal of Crystal Growth, 304(1), 264-269
Open this publication in new window or tab >>Homoepitaxial growth of Ti-Si-C MAX-phase thin films on bulk Ti3SiC2 substrates
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2007 (English)In: Journal of Crystal Growth, ISSN 0022-0248, E-ISSN 1873-5002, Vol. 304, no 1, p. 264-269Article in journal (Refereed) Published
Abstract [en]

Ti3SiC2 films were grown on polycrystalline Ti3SiC2 bulk substrates using DC magnetron sputtering. The crystallographic orientation of the film grains is shown to be determined by the respective substrate-grain orientation through homoepitaxial MAX-phase growth. For a film composition close to Ti:Si:C=3:1:2, the films predominantly consist of MAX phases, both Ti3SiC2 and the metastable Ti4SiC3. Lower Si content resulted in growth of TiC with Ti3SiC2 as a minority phase. Thus, MAX-phase heterostructures with preferred crystallographic relationships can also be realized.

Keywords
Scanning electron microscopy, Transmission electron microscopy, X-ray diffraction, Physical vapor deposition processes, Carbides, Nanomaterials
National Category
Natural Sciences
Identifiers
urn:nbn:se:liu:diva-14471 (URN)10.1016/j.jcrysgro.2007.02.014 (DOI)
Available from: 2007-05-14 Created: 2007-05-14 Last updated: 2017-12-13
Emmerlich, J., Music, D., Eklund, P., Wilhelmsson, O., Jansson, U., Schneider, J. M., . . . Hultman, L. (2007). Thermal stability of Ti3SiC2 thin films. Acta Materialia, 55(4), 1479-1488
Open this publication in new window or tab >>Thermal stability of Ti3SiC2 thin films
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2007 (English)In: Acta Materialia, ISSN 1359-6454, E-ISSN 1873-2453, Vol. 55, no 4, p. 1479-1488Article in journal (Refereed) Published
Abstract [en]

The thermal stability of Ti3SiC2(0 0 0 1) thin films is studied by in situ X-ray diffraction analysis during vacuum furnace annealing in combination with X-ray photoelectron spectroscopy, transmission electron microscopy and scanning transmission electron microscopy with energy dispersive X-ray analysis. The films are found to be stable during annealing at temperatures up to ∼1000 °C for 25 h. Annealing at 1100–1200 °C results in the rapid decomposition of Ti3SiC2 by Si out-diffusion along the basal planes via domain boundaries to the free surface with subsequent evaporation. As a consequence, the material shrinks by the relaxation of the Ti3C2 slabs and, it is proposed, by an in-diffusion of O into the empty Si-mirror planes. The phase transformation process is followed by the detwinning of the as-relaxed Ti3C2 slabs into (1 1 1)-oriented TiC0.67 layers, which begin recrystallizing at 1300 °C. Ab initio calculations are provided supporting the presented decomposition mechanisms.

Keywords
Ti3SiC2 thin films, Phase transformations, X-ray diffraction, Transmission electron microscopy, Ab initio electron theory
National Category
Natural Sciences
Identifiers
urn:nbn:se:liu:diva-14478 (URN)10.1016/j.actamat.2006.10.010 (DOI)
Available from: 2007-05-14 Created: 2007-05-14 Last updated: 2017-12-13
Rester, M., Neidhardt, J., Eklund, P., Emmerlich, J., Ljungcrantz, H., Hultman, L. & Mitterer, C. (2006). Annealing studies of nanocomposite Ti-Si-C thin films with respect to phase stability and tribological performance. Materials Science & Engineering: A, 429( 1-2), 90-95
Open this publication in new window or tab >>Annealing studies of nanocomposite Ti-Si-C thin films with respect to phase stability and tribological performance
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2006 (English)In: Materials Science & Engineering: A, ISSN 0921-5093, E-ISSN 1873-4936, Vol. 429, no 1-2, p. 90-95Article in journal (Refereed) Published
Abstract [en]

Nanocomposite Ti-Si-C thin films were deposited by dc magnetron sputtering from a Ti3SiC2 target onto Si(1 0 0) and high-speed steel substrates at 300 °C. The as-deposited films consisted of nanocrystalline (nc-) TiCx and amorphous (a-) SiCx, as determined by X-ray diffraction (XRD) and X-ray photoelectron spectroscopy (XPS). Annealing in vacuum up to 1450 °C resulted in improved crystallinity and a decreased volume fraction of the amorphous phase. Additionally, differential scanning calorimetry (DSC) was used to monitor heat flows connected to the respective reactions in the material, where a broad exothermic peak attributed to grain growth of crystalline TiCx appeared, while an exothermic reaction related to the formation of Ti3SiC2 was not detected. Tribological testing in a ball-on-disk setup was conducted at room temperature, 500 and 700 °C against an alumina counterpart. The room temperature measurement resulted in a coefficient of friction value of 0.8, at elevated temperatures the coefficient of friction decreased to 0.4. © 2006 Elsevier B.V. All rights reserved.

National Category
Natural Sciences
Identifiers
urn:nbn:se:liu:diva-34457 (URN)10.1016/j.msea.2006.05.053 (DOI)21494 (Local ID)21494 (Archive number)21494 (OAI)
Available from: 2009-10-10 Created: 2009-10-10 Last updated: 2017-12-13
Wilhelmsson, O., Palmquist, J.-P., Lewin, E., Emmerlich, J., Eklund, P., Persson, P., . . . Jansson, U. (2006). Deposition and characterization of ternary thin films within the Ti-Al-C system by DC magnetron sputtering. Journal of Crystal Growth, 291(1), 290-300
Open this publication in new window or tab >>Deposition and characterization of ternary thin films within the Ti-Al-C system by DC magnetron sputtering
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2006 (English)In: Journal of Crystal Growth, ISSN 0022-0248, E-ISSN 1873-5002, Vol. 291, no 1, p. 290-300Article in journal (Refereed) Published
Abstract [en]

The formation of ternary compounds within the Ti-Al-C system was studied by magnetron sputtering for thin-film deposition and first-principles calculations for phase stability. As-deposited films were characterized with X-ray diffraction (XRD) and high-resolution transmission electron microscopy (TEM). The hardness and Young's moduli of the material were studied by nanoindentation. Epitaxial and phase-pure films of Mn+1AXn phases Ti3AlC2 and Ti2AlC as well as the perovskite phase Ti3AlC were deposited on Al2O3(00l) wafers kept at temperatures between 800 and 900 °C. The only ternary phases observed at low temperatures (300 °C) were Ti3AlC and cubic (Ti,Al)C, the latter can be described as a metastable solid solution of Al in TiC similar to the more studied (Ti,Al)N system. The difficulties to form MAX phases at low substrate temperatures were attributed of requirement for a sufficient diffusivity to partition the elements corresponding to the relatively complex crystal structures with long c-axes. While MAX-phase synthesis at 800 °C is significantly lower than contemporary bulk sintering processes, a reduction of the substrate temperature towards 300 °C in the present thin-film deposition experiments resulted in stacking sequence variations and the intergrowth of (Ti,Al)C. © 2006 Elsevier B.V. All rights reserved.

Keywords
A1. Solid solutions, A3. PVD, B1. Carbides, B1. MAX-phase, B1. Perovksite
National Category
Engineering and Technology
Identifiers
urn:nbn:se:liu:diva-50222 (URN)10.1016/j.jcrysgro.2006.03.008 (DOI)
Available from: 2009-10-11 Created: 2009-10-11 Last updated: 2017-12-12
Magnuson, M., Mattesini, M., Wilhelmsson, O., Emmerlich, J., Palmquist, J.-P., Li, S., . . . Jansson, U. (2006). Electronic structure and chemical bonding in Ti4SiC3 investigated by soft x-ray emission spectroscopy and first-principles theory. Physical Review B. Condensed Matter and Materials Physics, 74(20)
Open this publication in new window or tab >>Electronic structure and chemical bonding in Ti4SiC3 investigated by soft x-ray emission spectroscopy and first-principles theory
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2006 (English)In: Physical Review B. Condensed Matter and Materials Physics, ISSN 1098-0121, E-ISSN 1550-235X, Vol. 74, no 20Article in journal (Refereed) Published
Abstract [en]

Theelectronic structure in the new transition-metal carbide Ti4SiC3 has beeninvestigated by bulk-sensitive soft x-ray emission spectroscopy and compared tothe well-studied Ti3SiC2 and TiC systems. The measured high-resolution TiL, C K, and Si L x-ray emission spectra arediscussed with ab initio calculations based on density-functional theory includingcore-to-valence dipole matrix elements. The detailed investigations of the Ti-Cand Ti-Si chemical bonds provide increased understanding of the physicalproperties of these nanolaminates. A strongly modified spectral shape isdetected for the intercalated Si monolayers due to Si 3phybridization with the Ti 3d orbitals. As a result ofrelaxation of the crystal structure and the charge-transfer from Ti(and Si) to C, the strength of the Ti-C covalentbond is increased. The differences between the electronic and crystalstructures of Ti4SiC3 and Ti3SiC2 are discussed in relation tothe number of Si layers per Ti layer in thetwo systems and the corresponding change of materials properties.

Keywords
band structure, crystal structure, bonds (chemical), titanium compounds, silicon compounds, X-ray emission spectra, ab initio calculations, density functional theory, laminates, nanocomposites, charge exchange
National Category
Natural Sciences
Identifiers
urn:nbn:se:liu:diva-17405 (URN)10.1103/PhysRevB.74.205102 (DOI)
Note

Original Publication:Martin Magnuson, M. Mattesini, O. Wilhelmsson, Jens Emmerlich, J.-P. Palmquist, S. Li, R. Ahuja, Lars Hultman, O. Eriksson and U. Jansson, Electronic structure and chemical bonding in Ti4SiC3 investigated by soft x-ray emission spectroscopy and first-principles theory, 2006, Physical Review B. Condensed Matter and Materials Physics, (74), 205102.http://dx.doi.org/10.1103/PhysRevB.74.205102Copyright: American Physical Societyhttp://www.aps.org/

Available from: 2009-03-23 Created: 2009-03-23 Last updated: 2018-06-04Bibliographically approved
Högberg, H., Emmerlich, J., Eklund, P., Wilhelmsson, O., Palmquist, J.-P., Jansson, U. & Hultman, L. (2006). Growth and characterization of epitaxial MAX-phase thin films from the Tin+1(Si,Ge,Sn)Cn systems. In: 11th International Ceramics Congress, CIMTEC,2006 (pp. 2648). Zürich: TransTech Publications
Open this publication in new window or tab >>Growth and characterization of epitaxial MAX-phase thin films from the Tin+1(Si,Ge,Sn)Cn systems
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2006 (English)In: 11th International Ceramics Congress, CIMTEC,2006, Zürich: TransTech Publications , 2006, p. 2648-Conference paper, Published paper (Refereed)
Abstract [en]

  

Place, publisher, year, edition, pages
Zürich: TransTech Publications, 2006
National Category
Natural Sciences
Identifiers
urn:nbn:se:liu:diva-35619 (URN)27975 (Local ID)27975 (Archive number)27975 (OAI)
Available from: 2009-10-10 Created: 2009-10-10 Last updated: 2016-08-31
Alami, J., Eklund, P., Emmerlich, J., Wilhelmsson, O., Jansson, U., Högberg, H., . . . Helmersson, U. (2006). High-power impulse magnetron sputtering of Ti-Si-C thin films from a Ti3SiC2 compound target. Thin Solid Films, 515(4), 1731-1736
Open this publication in new window or tab >>High-power impulse magnetron sputtering of Ti-Si-C thin films from a Ti3SiC2 compound target
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2006 (English)In: Thin Solid Films, ISSN 0040-6090, E-ISSN 1879-2731, Vol. 515, no 4, p. 1731-1736Article in journal (Refereed) Published
Abstract [en]

We have deposited Ti-Si-C thin films using high-power impulse magnetron sputtering (HIPIMS) from a Ti3SiC2 compound target. The as-deposited films were composite materials with TiC as the main crystalline constituent. X-ray diffraction and photoelectron spectroscopy indicated that they also contained amorphous SiC, and for films deposited on inclined substrates, crystalline Ti5Si3Cx. The film morphology was dense and flat, while films deposited with dc magnetron sputtering under comparable conditions were rough and porous. Due to the high degree of ionization of the sputtered species obtained in HIPIMS, it is possible to control the film composition, in particular the C content, by tuning the substrate inclination angle, the Ar process pressure, and the bias voltage.

Place, publisher, year, edition, pages
Institutionen för fysik, kemi och biologi, 2006
Keywords
HIPIMS, Titanium silicon carbide
National Category
Physical Sciences
Identifiers
urn:nbn:se:liu:diva-10437 (URN)10.1016/j.tsf.2006.06.015 (DOI)000242931900079 ()
Note

Original publication: J. Alami, P. Eklund, J. Emmerlich, O. Wilhelmsson, U. Jansson, H. Högberg, L. Hultman, & U. Helmersson, High-power impulse magnetron sputtering of Ti-Si-C thin films from a Ti3SiC2 compound target, 2006, Thin Solid Films, (515), 4, 1731-1736. http://dx.doi.org/10.1016/j.tsf.2006.06.015. Copyright: Elsevier B.V., http://www.elsevier.com/.

Available from: 2007-12-14 Created: 2007-12-14 Last updated: 2017-12-14Bibliographically approved
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