Above-room-temperature ferromagnetism in half-metallic Heusler compounds NiCrP, NiCrSe, NiCrTe, and NiVAs: A first-principles study
Above-room-temperature ferromagnetism in half-metallic Heusler compounds NiCrP, NiCrSe, NiCrTe, and NiVAs: A first-principles study
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DOI：
10.1063/1.2060941
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发表时间：
2005-05
影响因子：
3.2
通讯作者：
E. Şaşıoğlu;L. Sandratskii;Patrick Bruno
中科院分区：
文献类型：
--
作者：
E. Şaşıoğlu;L. Sandratskii;Patrick Bruno
本文研究了半金属Heusler化合物NiCrZ（Z=P，Se，Te）和NiVAs的原子间交换作用和居里温度。该研究是在密度泛函理论的框架内进行的。交换参数的计算是基于冻结磁振子方法。结果表明，NiCrZ中的交换相互作用强烈地依赖于Z成分。居里温度的计算内平均场和随机相位近似。两个估计值之间的差异与交换相互作用的性质有关。所有四个系统的预测居里温度都大大高于室温。讨论了半金属度与居里温度的关系。电荷载流子的高自旋极化和高居里温度的组合使这些Heusler合金成为自旋电子学应用的有趣候选者。
We study the interatomic exchange interactions and Curie temperatures in half-metallic semi-Heusler compounds NiCrZ (Z=P, Se, Te) and NiVAs. The study is performed within the framework of density functional theory. The calculation of exchange parameters is based on the frozen-magnon approach. It is shown that the exchange interactions in NiCrZ vary strongly depending on the Z constituent. The Curie temperature is calculated within mean field and random phase approximations. The difference between two estimated values is related to the properties of the exchange interactions. The predicted Curie temperatures of all four systems are considerably above room temperature. The relation between half-metallicity and the value of the Curie temperature is discussed. The combination of a high spin polarization of charge carriers and a high Curie temperature makes these Heusler alloys interesting candidates for spintronics applications.