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DOI	10.1039/c8ee00306h
	A valence balanced rule for discovery of 18-electron half-Heuslers with defects
	Anand S.; Xia K.; Hegde V.I.; Aydemir U.; Kocevski V.; Zhu T.; Wolverton C.; Snyder G.J.
发表日期	2018
ISSN	17545692
起始页码	1480
结束页码	1488
卷号	11 期号:6
英文摘要	Using first-principles DFT we systematically investigate the thermodynamic stability and off-stoichiometry in 108 nominal 19-electron half-Heusler (hH) compounds. We demonstrate unambiguously that considering a cation deficiency towards the off-stoichiometric valence balanced, VEC = 18 composition is necessary for explaining the stability of all previously reported nominal VEC = 19 compounds. This is understandable in terms of an energy benefit from valence balance considering the valence of each atom using Zintl chemistry that offsets the energy penalty of forming defects in nearly all cases. Thus, we propose a valence balanced rule to understand the ground state stability of half-Heuslers irrespective of stoichiometry and nominal electron count (8, 18 or 19). Using this generalized rule we (a) predict 16 previously unreported nominal 19-electron XYZ half-Heuslers and (b) rationalize the reports of giant off-stoichiometries in compounds such as Ti(1-x)NiSb which has been known for over 50 years. Of the 16 new compounds predicted here, Ti(1-x)PtSb was synthesized and the half-Heusler phase confirmed through X-ray studies. The flexibility in stoichiometry of the half-Heusler systems to attain a stable valence balanced composition by accommodating large defect concentrations opens up multiple dimensions for discovery of multi-component defective half-Heuslers based on intrinsic and extrinsic defects which compensate for the nominally non-18-electron count of the structure. © 2018 The Royal Society of Chemistry.
英文关键词	Ground state; Positive ions; Stoichiometry; Energy benefits; Energy penalties; Extrinsic defects; First principles; Forming defects; Multicomponents; Multiple dimensions; State stability; Defects; cation; concentration (composition); electrochemistry; electron; stoichiometry; thermodynamics; X-ray
语种	英语
来源期刊	Energy & Environmental Science
文献类型	期刊论文
条目标识符	http://gcip.llas.ac.cn/handle/2XKMVOVA/190236
作者单位	Department of Materials Science and Engineering, Northwestern University, Evanston, IL 60208, United States; State Key Laboratory of Silicon Materials, School of Materials Science and Engineering, Zhejiang University, Hangzhou, 310027, China; Department of Chemistry, Koc University Sariyer, Istanbul, 34450, Turkey; Key Laboratory of Advanced Materials and Applications for Batteries of Zhejiang Province, Zhejiang University, Hangzhou, 310027, China
推荐引用方式 GB/T 7714	Anand S.,Xia K.,Hegde V.I.,et al. A valence balanced rule for discovery of 18-electron half-Heuslers with defects[J],2018,11(6).
APA	Anand S..,Xia K..,Hegde V.I..,Aydemir U..,Kocevski V..,...&Snyder G.J..(2018).A valence balanced rule for discovery of 18-electron half-Heuslers with defects.Energy & Environmental Science,11(6).
MLA	Anand S.,et al."A valence balanced rule for discovery of 18-electron half-Heuslers with defects".Energy & Environmental Science 11.6(2018).