Nanoscale structural heterogeneity in Ni-rich half-Heusler TiNiSn
Nanoscale structural heterogeneity in Ni-rich half-Heusler TiNiSn
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DOI：
10.1063/1.4900497
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发表时间：
2014-10-28
影响因子：
3.2
通讯作者：
Seshadri, Ram
中科院分区：
文献类型：
--
作者：
Douglas, Jason E.;Chater, Philip A.;Seshadri, Ram
过量镍的TiNiSn半-Heusler化合物的结构影响，检查通过同步加速器X射线和中子散射的研究相结合，结合第一性原理密度泛函理论计算的超晶胞。尽管相图表明，TiNiSn是一个线化合物，没有固溶体，小x在TiNi 1-xSn确实有一个外观-从仔细分析的散射-一些溶解度，与过量的Ni占据间隙四面体网站的半Heusler结构。这里进行的分析将指出过量的Ni不是统计分布的，而是作为相干的纳米团簇发生的。能量学的第一原理计算，使用超级细胞进行，支持Ni的晶体团簇的情况下，而不是一个统计分布。(C)2014 AIP Publishing LLC.
The structural implications of excess Ni in the TiNiSn half-Heusler compound are examined through a combination of synchrotron x-ray and neutron scattering studies, in conjunction with first principles density functional theory calculations on supercells. Despite the phase diagram suggesting that TiNiSn is a line compound with no solid solution, for small x in TiNi1-xSn there is indeed an appearance-from careful analysis of the scattering-of some solubility, with the excess Ni occupying the interstitial tetrahedral site in the half-Heusler structure. The analysis performed here would point to the excess Ni not being statistically distributed, but rather occurring as coherent nanoclusters. First principles calculations of energetics, carried out using supercells, support a scenario of Ni interstitials clustering, rather than a statistical distribution. (C) 2014 AIP Publishing LLC.