Conditions for spin-gapless semiconducting behavior in Mn2CoAl inverse Heusler compound
Conditions for spin-gapless semiconducting behavior in Mn2CoAl inverse Heusler compound
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DOI：
10.1063/1.4867917
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发表时间：
2014-03-07
影响因子：
3.2
通讯作者：
Bluegel, S.
中科院分区：
文献类型：
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作者：
Galanakis, I.;Ozdogan, K.;Bluegel, S.
采用从头算电子结构计算方法，研究了反相Mn2CoAl Heusler化合物的自旋无带隙半导体（SGS）行为.我们表明，四方化的晶格，这可能会发生在薄膜生长过程中，保持完美的立方化合物的SGS字符。相反，原子交换，即使在不同的局部对称性的网站之间破坏SGS字符引起的半金属状态。此外，Co过剩的出现也导致半金属丰度。因此，我们建议，为了实现SGS行为在Mn2CoAl（和类似的SGS Heusler化合物）薄膜的生长过程中，应该尽量减少缺陷的发生，而晶格的小变形，由于晶格与衬底的失配，不起关键作用。(C)2014 AIP出版有限责任公司。
Employing ab initio electronic structure calculations, we investigate the conditions for spin-gapless semiconducting (SGS) behavior in the inverse Mn2CoAl Heusler compound. We show that tetragonalization of the lattice, which can occur during films growth, keeps the SGS character of the perfect cubic compound. On the contrary, atomic swaps even between sites with different local symmetry destroy the SGS character giving rise to a half-metallic state. Furthermore, the occurrence of Co-surplus leads also to half-metallicity. Thus, we propose that in order to achieve SGS behavior during the growth of Mn2CoAl (and similar SGS Heusler compounds) thin films, one should minimize the occurrence of defects, while small deformations of the lattice, due to the lattice mismatch with the substrate, do not play a crucial role. (C) 2014 AIP Publishing LLC.