論文

2017年8月

Theoretical investigation of solid solution states of Ti1-xVxH2

ACTA MATERIALIA
  • Noriko Otani
  • ,
  • Akihide Kuwabara
  • ,
  • Takafumi Ogawa
  • ,
  • Junko Matsuda
  • ,
  • Atsuto Seko
  • ,
  • Isao Tanaka
  • ,
  • Etsuo Akiba

134
開始ページ
274
終了ページ
282
記述言語
英語
掲載種別
研究論文(学術雑誌)
DOI
10.1016/j.actamat.2017.04.073
出版者・発行元
PERGAMON-ELSEVIER SCIENCE LTD

The solution states of metal atoms in Ti1-xVxH2, the stability of ordered ground-state structures, and the effect of metal-atom configurations on the bonding strength of H atoms are investigated by combining the cluster expansion method with first-principles calculations. Formation energies of all possible configurations of metal atoms in CaF2-type structures with up to sixteen metal atoms calculated using an optimized set of clusters are reported. Nine ground-state structures with different compositions are identified, most of which are found to have layered structures containing V bilayers. Analysis of the component clusters suggests that, while pair clusters contribute to formation of the layered structures, the higher-body clusters contribute more to stabilization of V bilayers than Ti bilayers. Based on calculations of short-range order parameters for all configurations of composition x = 1/2, low-energy structures including the layered structures appear to have a tendency for phase separation at the atomic scale. Order-disorder transition temperatures of the ground-state structures are estimated from Monte Carlo simulations to be less than 460 K. Comparison of lattice constants with experimental values as well as the low transition temperatures suggests that disordered solutions will be predominantly formed under typical synthesis conditions. In addition, we examine the stability of H atoms in different coordination environments and find that the metal-atom ordering does not greatly affect the local bonding between H and surrounding metal atoms. (C) 2017 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.

Web of Science ® 被引用回数 : 2

リンク情報
DOI
https://doi.org/10.1016/j.actamat.2017.04.073
Web of Science
https://gateway.webofknowledge.com/gateway/Gateway.cgi?GWVersion=2&SrcAuth=JSTA_CEL&SrcApp=J_Gate_JST&DestLinkType=FullRecord&KeyUT=WOS:000406987700026&DestApp=WOS_CPL
ID情報
  • DOI : 10.1016/j.actamat.2017.04.073
  • ISSN : 1359-6454
  • eISSN : 1873-2453
  • Web of Science ID : WOS:000406987700026

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