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Furlan, Andrej
Alternative names
Publications (10 of 17) Show all publications
Furlan, A., Jansson, U., Lu, J., Hultman, L. & Magnuson, M. (2015). Structure and bonding in amorphous iron carbide thin films. Journal of Physics: Condensed Matter, 27(4), 045002
Open this publication in new window or tab >>Structure and bonding in amorphous iron carbide thin films
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2015 (English)In: Journal of Physics: Condensed Matter, ISSN 0953-8984, E-ISSN 1361-648X, Vol. 27, no 4, p. 045002-Article in journal (Refereed) Published
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.

Place, publisher, year, edition, pages
Institute of Physics Publishing (IOPP), 2015
Keywords
iron carbide, thin film coatings, sputtering, synchrotron radiation, amorphous nanocomposites, TEM, RDF
National Category
Physical Sciences
Identifiers
urn:nbn:se:liu:diva-113089 (URN)10.1088/0953-8984/27/4/045002 (DOI)000348493500002 ()25567721 (PubMedID)
Note

We would like to thank the staff at the MAX IV Laboratory for experimental support, and Jill Sundberg, UU, for help with the Raman measurements. The work was supported by the Swedish Research Council (VR) by project, and Linnaeus grants (VR 2008-6582). MM, UJ and JL also acknowledge the Swedish Foundation for Strategic Research Synergy Project FUNCASE (RMA11-0029).

Available from: 2015-01-08 Created: 2015-01-08 Last updated: 2018-06-04
Furlan, A., Lu, J., Hultman, L., Jansson, U. & Magnuson, M. (2014). Crystallization characteristics and chemical bonding properties of nickel carbide thin film nanocomposites. Journal of Physics: Condensed Matter, 26(41), 415501-415512
Open this publication in new window or tab >>Crystallization characteristics and chemical bonding properties of nickel carbide thin film nanocomposites
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2014 (English)In: Journal of Physics: Condensed Matter, ISSN 0953-8984, E-ISSN 1361-648X, Vol. 26, no 41, p. 415501-415512Article in journal (Refereed) Published
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.

Place, publisher, year, edition, pages
Institute of Physics Publishing (IOPP), 2014
Keywords
Amorphous nanocomposite nickel carbide XRD TEM XAS SAED
National Category
Physical Sciences
Identifiers
urn:nbn:se:liu:diva-110752 (URN)10.1088/0953-8984/26/41/415501 (DOI)000343423600004 ()25237716 (PubMedID)
Available from: 2014-09-20 Created: 2014-09-20 Last updated: 2018-06-04Bibliographically approved
Furlan, A., Gueorguiev, G. K., Czigány, Z., Darakchieva, V., Braun, S., Correia, R., . . . Hultman, L. (2013). Structure and properties of phosphorus-carbide thin solid films. Thin Solid Films, 548(2), 247-254
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2013 (English)In: Thin Solid Films, ISSN 0040-6090, E-ISSN 1879-2731, Vol. 548, no 2, p. 247-254Article in journal (Refereed) Published
Abstract [en]

Phosphorus-carbide (CPx) thin films have been deposited by unbalanced reactive magnetron sputtering and investigated by TEM, XPS, SEM, ERDA, Raman scattering spectroscopy, nanoindentation testing, and four-point electrical probe techniques. As-deposited films with x=0.1 are electron amorphous with elements of FL structure and high mechanical resiliency with hardness of 34.4 GPa and elastic recovery of 72%. The electrical resistivity of the films are in the range 0.4-1.7 Ωcm for CP0.027, 1.4-22.9 Ωcm for CP0.1, and lower than the minimal value the four-point probe is able to detect for CPx with x≥0.2.

Keywords
Phosphorus carbide, thin films, magnetron sputtering
National Category
Other Engineering and Technologies not elsewhere specified
Identifiers
urn:nbn:se:liu:diva-17058 (URN)10.1016/j.tsf.2013.10.010 (DOI)000327530300039 ()
Available from: 2009-03-04 Created: 2009-03-04 Last updated: 2017-12-13Bibliographically approved
Broitman, E., Furlan, A., Geuorguiev, G. K., Czigany, Z., Högberg, H. & Hultman, L. (2012). Structural and Mechanical Properties of CNx and CPx Thin Solid Films. Key Engineering Materials, 488-489, 581-584
Open this publication in new window or tab >>Structural and Mechanical Properties of CNx and CPx Thin Solid Films
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2012 (English)In: Key Engineering Materials, ISSN 1013-9826, E-ISSN 1662-9795, Vol. 488-489, p. 581-584Article in journal (Refereed) Published
Abstract [en]

The inherent resiliency, hardness and relatively low friction coefficient of the fullerene-like (FL) allotrope of carbon nitride (CNx) thin solid films give them potential in numerous tribological applications. In this work, we study the substitution of N with P to grow FL-CPx to achieve better cross- and inter-linking of the graphene planes, improving thus the materials mechanical and tribological properties. The CNx and CPx films have been synthesized by DC magnetron sputtering. HRTEM have shown the CPx films exhibit a short range ordered structure with FL characteristics for substrate temperature of 300 degrees C and for a phosphorus content of 10-15 at.%. These films show better mechanical properties in terms of hardness and resiliency compared to those of the FL-CNx films. The low water adsorption of the films is correlated to the theoretical prediction for low density of dangling bonds in both, CNx and CPx. First-principles calculations based on Density Functional Theory (DFT) were performed to provide additional insight on the structure and bonding in CNx, CPx and a-C compounds.

Place, publisher, year, edition, pages
Trans Tech Publications, 2012
Keywords
carbon nitride; phosphorous-carbide; fullerene-like coatings; thin films; magnetron sputtering
National Category
Engineering and Technology
Identifiers
urn:nbn:se:liu:diva-87972 (URN)10.4028/www.scientific.net/KEM.488-489.581 (DOI)000306531200142 ()
Available from: 2013-01-28 Created: 2013-01-28 Last updated: 2017-12-06
Kostov Gueorguiev, G., Czigany, Z., Furlan, A., Stafström, S. & Hultman, L. (2011). Intercalation of P atoms in Fullerene-like CPx. CHEMICAL PHYSICS LETTERS, 501(4-6), 400-403
Open this publication in new window or tab >>Intercalation of P atoms in Fullerene-like CPx
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2011 (English)In: CHEMICAL PHYSICS LETTERS, ISSN 0009-2614, Vol. 501, no 4-6, p. 400-403Article in journal (Refereed) Published
Abstract [en]

The energy cost for P atom intercalation and corresponding structural implications during formation of Fullerene-like Phosphorus carbide (FL-CPx) were evaluated within the framework of Density Functional Theory. Single P atom interstitial defects in FL-CPx are energetically feasible and exhibit energy cost of 0.93-1.21 eV, which is comparable to the energy cost for experimentally confirmed tetragon defects and dangling bonds in CPx. A single P atom intercalation event in FL-CPx can increase the inter-sheet distance from 3.39-3.62 angstrom to 5.81-7.04 angstrom. These theoretical results are corroborated by Selected Area Electron Diffraction characterization of FL-CPx samples.

Place, publisher, year, edition, pages
Elsevier Science B.V., Amsterdam., 2011
National Category
Engineering and Technology
Identifiers
urn:nbn:se:liu:diva-66312 (URN)10.1016/j.cplett.2010.11.024 (DOI)000285829300047 ()
Note
Original Publication: Gueorgui Kostov Gueorguiev, Zs Czigany, Andrej Furlan, Sven Stafström and Lars Hultman, Intercalation of P atoms in Fullerene-like CPx, 2011, CHEMICAL PHYSICS LETTERS, (501), 4-6, 400-403. http://dx.doi.org/10.1016/j.cplett.2010.11.024 Copyright: Elsevier Science B.V., Amsterdam. http://www.elsevier.com/ Available from: 2011-03-11 Created: 2011-03-11 Last updated: 2016-08-31
Kostov Gueorguiev, G., Broitman, E., Furlan, A., Stafström, S. & Hultman, L. (2009). Dangling bond energetics in carbon nitride and phosphorus carbide thin films with fullerene-like and amorphous structure. CHEMICAL PHYSICS LETTERS, 482(1-3), 110-113
Open this publication in new window or tab >>Dangling bond energetics in carbon nitride and phosphorus carbide thin films with fullerene-like and amorphous structure
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2009 (English)In: CHEMICAL PHYSICS LETTERS, ISSN 0009-2614, Vol. 482, no 1-3, p. 110-113Article in journal (Refereed) Published
Abstract [en]

The energy cost for dangling bond formation in Fullerene-like Carbon Nitride (FL-CNx) and Phosphorus carbide (FL-CPx) as well as their amorphous counterparts: a-CNx, a-CPx, and a-C has been calculated within the framework of Density Functional Theory and compared with surface water adsorption measurements. The highest energy cost is found in the FL-CNx ( about 1.37 eV) followed by FL-CPx compounds (0.62-1.04 eV). (C) 2009 Elsevier B. V. All rights reserved.

National Category
Natural Sciences
Identifiers
urn:nbn:se:liu:diva-51780 (URN)10.1016/j.cplett.2009.09.083 (DOI)
Note
Original Publication: Gueorgui Kostov Gueorguiev, E Broitman, Andrej Furlan, Sven Stafström and Lars Hultman, Dangling bond energetics in carbon nitride and phosphorus carbide thin films with fullerene-like and amorphous structure, 2009, CHEMICAL PHYSICS LETTERS, (482), 1-3, 110-113. http://dx.doi.org/10.1016/j.cplett.2009.09.083 Copyright: Elsevier Science B.V., Amsterdam. http://www.elsevier.com/ Available from: 2009-11-18 Created: 2009-11-17 Last updated: 2016-08-31
Furlan, A. (2009). Fullerene-like CNx and CPx Thin Films; Synthesis, Modeling, and Applications. (Doctoral dissertation). Linköping: Linköping University Electronic Press
Open this publication in new window or tab >>Fullerene-like CNx and CPx Thin Films; Synthesis, Modeling, and Applications
2009 (English)Doctoral thesis, comprehensive summary (Other academic)
Abstract [en]

This Thesis concerns the development of fullerene-like (FL) carbon nitride (CNx) thin films and the discovery of phosphorus-carbide (CPx) compounds. The work dedicated to CPx include first-principles theoretical simulations of the growth and properties of FL-CPx structures. I have employed DC magnetron sputtering methods to synthesize both CNx and CPx thin films. The deposition conditions for CPx films were chosen on the basis of the theoretical results as well as from the experience from the deposition of FL-CNx thin films.

The characterization of the CPx films is divided into three main directions: structural characterization by transmission electron microscopyand scanning electron microscopy, analysis of the amount of elements and chemical bonds presentin the structure by X-ray photoelectron spectroscopy and Auger spectroscopy, and mechanicalproperty analysis by nanoindentation. The CPx films exhibit a short range orderedstructure with FL characteristics for substrate temperature of 300 °C and for a phosphorus content of 10-15 at.%, which isconsistent with the theoretical findings. These films also displayed the best mechanical properties in terms of hardness and resiliency, which are better than those of the corresponding FL-CNx films.

For the FL-CNx thin film material, I find that the surface water adsorption is lower compared to commercial computer hard disk top coatings. Following that line the dangling bonds in FL-CNx coatings have been investigated  by electron spin resonance (ESR). The absence of ESR signal for FL-CNx indicates very low density of dangling bonds in the material, which explains the low water adsorption tendency.

The potential for using highly elastic FL-CNx coatings in an automotive valve-train environment has also been investigated. CNx coatings of different nitrogen content were investigated using microscopy, wear testing, nanoindentation testing, and in an experimental cam-tappet testing rig. The FL-CNx coating with the higher value of hardness/elastic modulus showed greater durability in cam-tappet wear testing.

Place, publisher, year, edition, pages
Linköping: Linköping University Electronic Press, 2009. p. 60
Series
Linköping Studies in Science and Technology. Dissertations, ISSN 0345-7524 ; 1247
Keywords
Phosphorus-carbide (CPx), carbon nitride (CNx), thin films, resilient coatings, magnetron sputtering, theoretical modeling
National Category
Other Engineering and Technologies not elsewhere specified
Identifiers
urn:nbn:se:liu:diva-17126 (URN)978-91-7393-676-7 (ISBN)
Public defence
2009-03-30, Planck, Fysikhuset, Campus Valla, Linköpings universitet, Linköping, 10:15 (English)
Opponent
Supervisors
Available from: 2009-03-24 Created: 2009-03-06 Last updated: 2016-08-31Bibliographically approved
Berlind, T., Furland, A., Czigany, Z., Neidhardt, J., Hultman, L. & Arwin, H. (2009). Spectroscopic ellipsometry characterization of amorphous carbon and amorphous,graphitic and fullerene-like carbon nitride thin films. Thin Solid Films, 517(24), 6652-6658
Open this publication in new window or tab >>Spectroscopic ellipsometry characterization of amorphous carbon and amorphous,graphitic and fullerene-like carbon nitride thin films
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2009 (English)In: Thin Solid Films, ISSN 0040-6090, E-ISSN 1879-2731, Vol. 517, no 24, p. 6652-6658Article in journal (Refereed) Published
Abstract [en]

Carbon nitride (CNx) and amorphous carbon (a-C) thin films are deposited by reactive magnetron sputtering onto silicon (001) wafers under controlled conditions to achieve amorphous, graphitic and fullerene-like microstructures. As-deposited films are analyzed by Spectroscopic Ellipsometry in the UV–VIS–NIR and IR spectral ranges in order to get further insight into the bonding structure of the material. Additional characterization is performed by High Resolution Transmission Electron Microscopy, X-ray Photoelectron Spectroscopy, and Atomic Force Microscopy. Between eight and eleven resonances are observed and modeled in the ellipsometrically determined optical spectra of the films. The largest or the second largest resonance for all films is a feature associated with C–N or C–C modes. This feature is generally associated with sp3 C–N or sp3 C–C bonds, which for the nitrogen-containing films instead should be identified as a three-fold or two-fold sp2 hybridization of N, either substituted in a graphite site or in a pyridine-like configuration, respectively. The π→πlow asterisk electronic transition associated with sp2 C bonds in carbon films and with sp2 N bonds (as N bonded in pyridine-like manner) in CNx films is also present, but not as strong. Another feature present in all CNx films is a resonance associated with nitrile often observed in carbon nitrides. Additional resonances are identified and discussed and moreover, several new, unidentified resonances are observed in the ellipsometric spectra.

Place, publisher, year, edition, pages
Elsevier, 2009
Keywords
Carbon nitride; Amorphous carbon; Spectroscopic ellipsometry; Spectral decomposition; Fullerene-like; Structural properties; X-ray photoelectron spectroscopy; Transmission electron microscopy
National Category
Natural Sciences
Identifiers
urn:nbn:se:liu:diva-19705 (URN)10.1016/j.tsf.2009.04.065 (DOI)
Note
Original Publication: Torun Berlind, Andrej Furland, Zs. Czigany, Jörg Neidhardt, Lars Hultman and Hans Arwin, Spectroscopic ellipsometry characterization of amorphous carbon and amorphous,graphitic and fullerene-like carbon nitride thin films, 2009, Thin Solid Films, (517), 24, 6652-6658. http://dx.doi.org/10.1016/j.tsf.2009.04.065 Copyright: Elsevier Science B.V., Amsterdam. http://www.elsevier.com/ Available from: 2009-07-16 Created: 2009-07-16 Last updated: 2017-12-13Bibliographically approved
Broitman, E., Furlan, A., Kostov Gueorguiev, G., Czigany, Z., Tarditi, A. M., Gellman, A. J., . . . Hultman, L. (2009). Water adsorption on phosphorous-carbide thin films. Surface & Coatings Technology, 204(6-7), 1035-1039
Open this publication in new window or tab >>Water adsorption on phosphorous-carbide thin films
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2009 (English)In: Surface & Coatings Technology, ISSN 0257-8972, E-ISSN 1879-3347, Vol. 204, no 6-7, p. 1035-1039Article in journal (Refereed) Published
Abstract [en]

Amorphous phosphorous-carbide films have been considered as a new tribological coating material with unique electrical properties. However, such CPx films have not found practical use until now because they tend to oxidize/hydrolyze rapidly when in contact with air. Recently, we demonstrated that CPx thin films with a fullerene-like structure can be deposited by magnetron sputtering, whereby the structural incorporation of P atoms induces the formation of strongly bent and inter-linked graphene planes. Here, we compare the uptake of water in fullerene-like phosphorous-carbide (FL-CPx) thin films with that in amorphous phosphorous-carbide (a-CPx), and amorphous carbon (a-C) thin films. Films of each material were deposited on quartz crystal substrates by reactive DC magnetron sputtering to a thickness in the range 100-300 nm. The film microstructure was characterized by X-ray photoelectron spectroscopy, and high resolution transmission electron microscopy. A quartz crystal microbalance placed in a vacuum chamber was used to measure their water adsorption. Measurements indicate that FL-CPx films adsorbed less water than the a-CPx and a-C ones. To provide additional insight into the atomic structure of defects in the FL-CPx and a-CPx compounds, we performed first-principles calculations within the framework of density functional theory. Cohesive energy comparison reveals that the energy cost formation for dangling bonds in different configurations is considerably higher in FL-CPx than for the amorphous films. Thus, the modeling confirms the experimental results that dangling bonds are less likely in FL-CPx than in a-CPx and a-C films.

Keywords
Phosphorous carbide; Dangling bonds; Water adsorption; Density functional theory
National Category
Engineering and Technology
Identifiers
urn:nbn:se:liu:diva-52884 (URN)10.1016/j.surfcoat.2009.06.003 (DOI)
Available from: 2010-01-13 Created: 2010-01-12 Last updated: 2017-12-12
Furlan, A., Gueorguiev, G. K., Czigány, Z., Högberg, H., Braun, S., Stafström, S. & Hultman, L. (2008). Synthesis of phosphorus-carbide thin films by magnetron sputtering. physica status solidi (RRL) - Rapid Research Letters, 2(4), 191-193
Open this publication in new window or tab >>Synthesis of phosphorus-carbide thin films by magnetron sputtering
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2008 (English)In: physica status solidi (RRL) - Rapid Research Letters, ISSN 1862-6254, Vol. 2, no 4, p. 191-193Article in journal (Refereed) Published
Abstract [en]

Phosphorus-carbide, CPx (0.025≤x≤0.1) thin films have beensynthesized by magnetron sputtering from pressed graphite-phosphorustargets. The films were characterized by X-ray photoelectron spectroscopy,transmission electron microscopy and diffraction, andnanoindentation. CP0.02 exhibits C-P bonding in an amorphous structure with elements of curved grapheneplanes, yielding a material with unique short range order. These features are consistent with what has been predicted by our results of theoreticallymodeled synthetic growth of CPx. The films are mechanicallyresilient with hardness up to 24 GPa and elastic recovery upto 72%.

Place, publisher, year, edition, pages
Wiley InterScience, 2008
Keywords
Phosphorus-carbide (CPx), thin films, magnetron sputtering, resilient material
National Category
Other Engineering and Technologies not elsewhere specified
Identifiers
urn:nbn:se:liu:diva-17114 (URN)
Available from: 2009-03-06 Created: 2009-03-06 Last updated: 2016-08-31Bibliographically approved
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