Stability of ferromagnetism in the half-metallic pnictides and similar compounds: a first-principles study
Stability of ferromagnetism in the half-metallic pnictides and similar compounds: a first-principles study
复制标题
DOI：
10.1088/0953-8984/17/25/018
复制
发表时间：
2005-03
期刊：
影响因子：
--
通讯作者：
E. Şaşıoğlu;I. Galanakis;L. Sandratskii;P. Bruno
中科院分区：
文献类型：
--
作者：
E. Şaşıoğlu;I. Galanakis;L. Sandratskii;P. Bruno
基于第一性原理电子结构计算，采用冻结磁振子近似，研究了闪锌矿结构的一系列过渡金属二元合金的交换作用，并在平均场近似和随机相近似下计算了居里温度。我们研究了两种铬化合物，CrAs和CrSe，以及四种锰化合物，MnSi，MnGe，MnAs和MnC。MnC、MnSi和MnGe与Cras等价，MnS与Crse等电子。CrAs、MnSi和MnGe的铁磁性特别稳定：这三种化合物的居里温度都在1000K左右，而CrSe和MnAs在压缩晶格时表现出反铁磁性的趋势。在MNC中，与其他五种化合物不同，半金属能隙位于多数自旋通道中。较大的半金属带隙、很高的居里温度、铁磁性随晶格参数变化的稳定性以及半导体上的共格生长使它们成为最有希望用于自旋电子器件的候选材料。
Based on first-principles electron structure calculations and employing the frozen-magnon approximation, we study the exchange interactions in a series of transition-metal binary alloys crystallizing in the zinc-blende structure and calculate the Curie temperature within both the mean-field approximation and random-phase approximation. We study two Cr compounds, CrAs and CrSe, and four Mn compounds, MnSi, MnGe, MnAs and MnC. MnC, MnSi and MnGe are isovalent to CrAs and MnAs is isoelectronic to CrSe. Ferromagnetism is particular stable for CrAs, MnSi and MnGe: all three compounds show Curie temperatures around 1000 K. On the other hand, CrSe and MnAs show a tendency to antiferromagnetism when compressing the lattice. In MnC the half-metallic gap is located in the majority-spin channel, in contrast to the other five compounds. The large half-metallic gaps, very high Curie temperatures, the stability of the ferromagnetism with respect to the variation of the lattice parameter and a coherent growth on semiconductors make MnSi and CrAs the most promising candidates for use in spintronics devices.