第一性原理研究闪锌矿结构MnSb和MnBi半金属性和磁性的稳定性

采用基于第一性原理的全势能线性缀加平面波方法对闪锌矿结构MnSb和MnBi的电子结构进行自旋极化计算。闪锌矿结构MnSb和MnBi处于晶格平衡时都是半金属性的，并且它们自旋向下电子能带带隙分别是1.32eV 和1.27eV。闪锌矿结构MnSb和MnBi的自旋总磁矩都为4.00μB/formula，总磁矩主要来源于Mn的原子磁矩，Sb和Bi的原子磁矩对总磁矩的贡献很小而且为负值，它们具有明显的铁磁性特征. 使晶体晶格在±10%的范围内发生各向同性形变，对闪锌矿结构MnSb和MnBi的电子结构进行计算. 计算结果表明，当晶格各向同性形变分别为-1 % ~ 10 %和-4 % ~10 %时，闪锌矿结构MnSb和MnBi仍然保持半金属铁磁性，并且总磁矩都稳定于4.00μB/formula.

Stability of half-metallicity and magnetism of zinc-blende MnSb and MnBi: A first-principles investigation

Using the first-principles full-potential linearized augmented plane wave (FP-LAPW) method, the spin-polarized calculations of electronic structure for the zinc-blende MnSb and MnBi have been performed. Zinc-blende MnSb and MnBi at their equilibrium lattice constants are half-metallic with spin-down energy gaps of 1.32 and 1.27eV, respectively. The two compounds have a same total magnetic moment of 4.00 µB/formula. The total magnetic moment comes mostly from magnetic moment on Mn, and Sb and/or Bi contribute small but negative moment to it. The electronic structure of zinc-blende MnSb and MnBi have been calculated with the lattice uniform strain between -10% and +10%. The calculated results indicate that zinc-blende MnSb and MnBi can maintain half-metallic ferromagnetism and keep the same total magnetic moment of 4.00 µB/formula from -1% to 10% and from -4% to 10% uniform strain, respectively.