First-principles study of half-metallic ferromagnetism and structural stability of CrxZn1−xTe
First-principles study of half-metallic ferromagnetism and structural stability of CrxZn1−xTe
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DOI：
10.1088/0022-3727/40/21/045
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发表时间：
2007-10
期刊：
影响因子：
--
通讯作者：
Yong Liu;Banggui Liu
中科院分区：
文献类型：
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作者：
Yong Liu;Banggui Liu
本文报道了用第一性原理系统地研究了掺铬浓度高达0.5的掺铬ZnTe的结构性质、电子结构和磁性。我们充分优化了所有相关的结构，包括铁磁和反铁磁，以及它们的内部原子位置。我们的计算表明，它们是半金属铁磁体，半金属带隙大于0.6 eV。我们的计算结果与只有掺杂浓度很小的大块样品才能稳定的事实是一致的，这要归功于熵效应。另一方面，在非平衡方法制备的薄膜中，实验上获得了高达20%的铬掺杂浓度。计算结果表明，用非平衡方法可以在高质量的−-xTe薄膜样品中实现半金属铁磁性。我们用Pd杂化和由此产生的d主带的大的交换分裂来解释半金属的铁磁性。与适当的半导体兼容，这些材料，至少其中一些，可能在自旋电子学中有用。
We report a systematic first-principles study of structural properties, electronic structures and magnetic properties of Cr doped ZnTe with the Cr concentration up to 0.5. We fully optimize all the structures concerned, both ferromagnetic and antiferromagnetic, and their internal atomic positions. Our calculations show that they are half-metallic ferromagnets with half-metallic gaps over 0.6 eV. Our calculated results are consistent with the fact that only those bulk samples with very small doping concentrations can be stable thanks to the entropy effect. On the other hand, up to 20% Cr doping concentrations have been achieved experimentally in thin films fabricated with nonequilibrium methods. Our calculated results indicate that half-metallic ferromagnetism can be realized in high-quality thin film samples of CrxZn1−xTe with nonequilibrium methods. We explain the half-metallic ferromagnetism in terms of a pd hybridization and resulting large exchange splitting of d-dominated bands. Compatible with appropriate semiconductors, these materials, at least some of them, could be useful in spintronics.