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Title: M{sub n+1}AX{sub n} phases in the Ti-Si-C system studied by thin-film synthesis and ab initio calculations

Abstract

Thin films of M{sub n+1}AX{sub n} layered compounds in the Ti-Si-C system were deposited on MgO(111) and Al{sub 2}O{sub 3}(0001) substrates held at 900 deg. C using dc magnetron sputtering from elemental targets of Ti, Si, and C. We report on single-crystal and epitaxial deposition of Ti{sub 3}SiC{sub 2} (the previously reported MAX phase in the Ti-Si-C system), a previously unknown MAX phase Ti{sub 4}SiC{sub 3} and another type of structure having the stoichiometry of Ti{sub 5}Si{sub 2}C{sub 3} and Ti{sub 7}Si{sub 2}C{sub 5}. The latter two structures can be viewed as an intergrowth of 2 and 3 or 3 and 4 M layers between each A layer. In addition, epitaxial films of Ti{sub 5}Si{sub 3}C{sub x} were deposited and Ti{sub 5}Si{sub 4} is also observed. First-principles calculations, based on density functional theory (DFT) of Ti{sub n+1}SiC{sub n} for n=1,2,3,4 and the observed intergrown Ti{sub 5}Si{sub 2}C{sub 3} and Ti{sub 7}Si{sub 2}C{sub 5} structures show that the calculated difference in cohesive energy between the MAX phases reported here and competing phases (TiC, Ti{sub 3}SiC{sub 2}, TiSi{sub 2}, and Ti{sub 5}Si{sub 3}) are very small. This suggests that the observed Ti{sub 5}Si{sub 2}C{sub 3} and Ti{sub 7}Si{sub 2}C{sub 5} structures atmore » least should be considered as metastable phases. The calculations show that the energy required for insertion of a Si layer in the TiC matrix is independent of how close the Si layers are stacked. Hardness and electrical properties can be related to the number of Si layers per Ti layer. This opens up for designed thin film structures the possibility to tune properties.« less

Authors:
; ;  [1]; ; ; ; ;  [2]; ; ; ;  [3]
  1. Uppsala University, Department of Materials Chemistry, Angstroem Laboratory, P.O. Box 538 SE-751 21 Uppsala (Sweden)
  2. Uppsala University, Department of Physics, Angstroem Laboratory, P.O. Box 530 SE-751 21 Uppsala (Sweden)
  3. Linkoeping University, Department of Physics, IFM, Thin Film Physics Division, SE-581 83 Linkoeping (Sweden)
Publication Date:
OSTI Identifier:
20664932
Resource Type:
Journal Article
Journal Name:
Physical Review. B, Condensed Matter and Materials Physics
Additional Journal Information:
Journal Volume: 70; Journal Issue: 16; Other Information: DOI: 10.1103/PhysRevB.70.165401; (c) 2004 The American Physical Society; Country of input: International Atomic Energy Agency (IAEA); Journal ID: ISSN 1098-0121
Country of Publication:
United States
Language:
English
Subject:
75 CONDENSED MATTER PHYSICS, SUPERCONDUCTIVITY AND SUPERFLUIDITY; 36 MATERIALS SCIENCE; ALUMINIUM OXIDES; BINDING ENERGY; DENSITY FUNCTIONAL METHOD; ELECTRICAL PROPERTIES; FERMI LEVEL; HARDNESS; LAYERS; MAGNESIUM OXIDES; MAGNETRONS; MONOCRYSTALS; SILICON COMPOUNDS; SPUTTERING; STOICHIOMETRY; SURFACE COATING; SYNTHESIS; THIN FILMS; TITANIUM CARBIDES; TRANSMISSION ELECTRON MICROSCOPY; VAPOR PHASE EPITAXY; X-RAY DIFFRACTION

Citation Formats

Palmquist, J -P, Wilhelmsson, O, Jansson, U, Li, S, Katsnelson, M I, Johansson, B, Ahuja, R, Eriksson, O, Persson, P O.A., Emmerlich, J, Hoegberg, H, and Hultman, L. M{sub n+1}AX{sub n} phases in the Ti-Si-C system studied by thin-film synthesis and ab initio calculations. United States: N. p., 2004. Web. doi:10.1103/PhysRevB.70.165401.
Palmquist, J -P, Wilhelmsson, O, Jansson, U, Li, S, Katsnelson, M I, Johansson, B, Ahuja, R, Eriksson, O, Persson, P O.A., Emmerlich, J, Hoegberg, H, & Hultman, L. M{sub n+1}AX{sub n} phases in the Ti-Si-C system studied by thin-film synthesis and ab initio calculations. United States. doi:10.1103/PhysRevB.70.165401.
Palmquist, J -P, Wilhelmsson, O, Jansson, U, Li, S, Katsnelson, M I, Johansson, B, Ahuja, R, Eriksson, O, Persson, P O.A., Emmerlich, J, Hoegberg, H, and Hultman, L. Fri . "M{sub n+1}AX{sub n} phases in the Ti-Si-C system studied by thin-film synthesis and ab initio calculations". United States. doi:10.1103/PhysRevB.70.165401.
@article{osti_20664932,
title = {M{sub n+1}AX{sub n} phases in the Ti-Si-C system studied by thin-film synthesis and ab initio calculations},
author = {Palmquist, J -P and Wilhelmsson, O and Jansson, U and Li, S and Katsnelson, M I and Johansson, B and Ahuja, R and Eriksson, O and Persson, P O.A. and Emmerlich, J and Hoegberg, H and Hultman, L},
abstractNote = {Thin films of M{sub n+1}AX{sub n} layered compounds in the Ti-Si-C system were deposited on MgO(111) and Al{sub 2}O{sub 3}(0001) substrates held at 900 deg. C using dc magnetron sputtering from elemental targets of Ti, Si, and C. We report on single-crystal and epitaxial deposition of Ti{sub 3}SiC{sub 2} (the previously reported MAX phase in the Ti-Si-C system), a previously unknown MAX phase Ti{sub 4}SiC{sub 3} and another type of structure having the stoichiometry of Ti{sub 5}Si{sub 2}C{sub 3} and Ti{sub 7}Si{sub 2}C{sub 5}. The latter two structures can be viewed as an intergrowth of 2 and 3 or 3 and 4 M layers between each A layer. In addition, epitaxial films of Ti{sub 5}Si{sub 3}C{sub x} were deposited and Ti{sub 5}Si{sub 4} is also observed. First-principles calculations, based on density functional theory (DFT) of Ti{sub n+1}SiC{sub n} for n=1,2,3,4 and the observed intergrown Ti{sub 5}Si{sub 2}C{sub 3} and Ti{sub 7}Si{sub 2}C{sub 5} structures show that the calculated difference in cohesive energy between the MAX phases reported here and competing phases (TiC, Ti{sub 3}SiC{sub 2}, TiSi{sub 2}, and Ti{sub 5}Si{sub 3}) are very small. This suggests that the observed Ti{sub 5}Si{sub 2}C{sub 3} and Ti{sub 7}Si{sub 2}C{sub 5} structures at least should be considered as metastable phases. The calculations show that the energy required for insertion of a Si layer in the TiC matrix is independent of how close the Si layers are stacked. Hardness and electrical properties can be related to the number of Si layers per Ti layer. This opens up for designed thin film structures the possibility to tune properties.},
doi = {10.1103/PhysRevB.70.165401},
journal = {Physical Review. B, Condensed Matter and Materials Physics},
issn = {1098-0121},
number = 16,
volume = 70,
place = {United States},
year = {2004},
month = {10}
}