【摘要】 基于密度泛函理论的GGA计算,我们研究了LiMgPbSb型Heusler合金CoFeTiSb电子结构,发现CoFeTiSb在费米面处存在100%的自旋极化率,并且具有2μB的原胞总磁矩.此外,我们考虑了Co-Fe、Co-Ti和Fe-Ti交换无序对CoFeTiSb合金电子结构的影响,发现这三种交换无序均使得CoFeTiSb完全丧失了半金属性,在Co-Fe交换无序下,CoFeTiSb合金具有85%的自旋极化率,而在Co-Ti无序下,CoFeTiSb合金的自旋极化率只有5%.更多还原

【Abstract】 By using generalized gradient approximation( GGA) scheme within the density functional theory( DFT),the electronic structures of quaternary LiMgPbSb-type Heusler alloy CoFeTiSb were investigated. The spin-polarization of 100% at the Fermi level and cell magnetic moment of 2 μB were detected. Furthermore,the influences of Co-Fe、Co-Ti and Fe-Ti swap disorder on its electronic structure have been concerned in CoFeTiSb alloy. As a result,the half-metallicity of CoFeTiSb alloy is destroyed by three swap disorder effects mentioned above. Only spin-polarization values of 85% for Co-Fe disorder and 5% for Co-Ti disorder are retained in CoFeTiSb alloy.更多还原