摘要
基于密度泛函理论(DFT),使用广义梯度近似(GGA)和局域密度近似(LDA)研究了Heusler合金Co2MnAl1-xGex(x=0、0.25、0.5、0.75、1)的磁性和电子结构。随着掺杂浓度x的增加,合金的晶格常数和磁矩都线性增加,分别很好地满足Vegard和S-P规律。对于整个合金系列,随x的增加,自旋向下带带隙宽度略有减少,费米面向高能移动。由于Co2MnAl0.5Ge0.5合金的费米面恰好居于其自旋向下带带隙中部,此时合金具有最好的半金属稳定性,预期在磁隧道结器件中能实现高的自旋极化率。
Based on the density functional theory （DFT）, the generalized gradient approximation method （GGA） and the local density approximation method （LDA） were applied to calculate the magnetism, electronic structures and half-metallicity of Heusler alloys Co2MnAl1-xGex
（x=0,0. 25,0. 5,0. 75,1）. The lattice parameters and the magnetic moment of the alloys increased linearly with increase of Ge content, meeting the regard law and the S-P behavior well, respectively. Furthermore, the width of the spin-down gap slightly decreased and the fermi level moved up to higher energy level with increase of x. Since the fermi level locates in the middle of the spin-down gap, the Co2 MnA10. 5Ge0. 5 alloy presents a perfect half-metallic stability, and is expected to have a high spin polarization with the potential of magnetic tunnel junction application.
出处
《材料导报》
EI
CAS
CSCD
北大核心
2012年第4期1-4,8,共5页
Materials Reports
基金
贵州省教育厅自然科学研究项目([2009]331
20100084)
合肥市科技研发基金([2010]08)
贵州省科学技术基金([2011]2364)
