Curie temperatures of III-V diluted magnetic semiconductors calculated from first principles
Curie temperatures of III-V diluted magnetic semiconductors calculated from first principles
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DOI：
10.1209/epl/i2003-00191-8
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发表时间：
2003-02-01
期刊：
影响因子：
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通讯作者：
Katayama-Yoshida, H
中科院分区：
文献类型：
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作者：
Sato, K;Dederics, PH;Katayama-Yoshida, H
从第一性原理出发计算了稀释磁性半导体（Ga, Mn） As、（Ga, Mn） N、（Ga, Cr） As和（Ga, Cr） N的居里温度。采用Korringa-Kohn-Rostoker方法结合相干势近似，在局域自旋密度近似下计算电子结构，以描述取代和自旋无序。从铁磁态和自旋玻璃态之间的总能量差出发，利用平均场近似中海森堡模型的映射，实现了对居里温度的真实估计。还研究了其他载流子掺杂处理的影响。（Ga, Mn） N、（Ga, Cr） As和（Ga, Cr） N的居里温度均高于室温。空穴掺杂后，（Ga, Mn） N的居里温度进一步升高，而（Ga, Mn） As的居里温度趋于平稳。
Curie temperatures of the diluted magnetic semiconductors (Ga, Mn) As, (Ga, Mn) N, (Ga, Cr) As and (Ga, Cr) N are evaluated from first principles. The electronic structure is calculated in the local spin density approximation by using the Korringa-Kohn-Rostoker method combined with the coherent potential approximation to describe the substitutional and spin disorder. From the total energy differences between the ferromagnetic state and the spin-glass state, realistic estimations of Curie temperatures are achieved by using a mapping on the Heisenberg model in the mean-field approximation. Effects of additional carrier doping treatments are also investigated. Very large Curie temperatures are obtained, lying above room temperature for ( Ga, Mn) N, ( Ga, Cr) As and ( Ga, Cr) N. Upon hole doping the Curie temperature of (Ga, Mn) N further increases, while (Ga, Mn) As shows a plateau behavior.