密度泛函理论研究闪锌矿结构CrTe和VTe半金属铁磁性的稳定性

Density functional theory study on stability of half-metallic ferromagnetism of zinc-blende CrTe and VTe

采用基于密度泛函理论的全势能线性缀加平面波方法对闪锌矿结构CrTe和VTe的电子结构进行自旋极化计算.闪锌矿相CrTe和VTe处于平衡晶格常数时都是半金属性的,它们自旋向下子能带的带隙分别是2.82 eV和2.70 eV,半金属隙分别是0.89 eV和0.33 eV.使晶体相对于平衡晶格在士10%的范围内发生各向同性形变,对闪锌矿相CrTe和VTe的电子结构进行计算,计算结果表明相对于平衡晶格的各向同性形变分别为-6%～10%和-3%～10%时它们仍然具有半金属性质;与此同时,在以上相同的形变范围内闪锌矿相CrTe和VTe的总磁矩分别稳定于4.00μB/formula和3.00 μB/formula.在晶体相对于平衡晶格发生各向同性形变分别为—6%～10%和—3%～10%时,闪锌矿相CrTe和VTe能保持半金属铁磁性.

Using the full-potential linearized augmented plane wave （FP-LAPW） method based on the density functional theory, the spin-polarized calculations of electronic structure for the zinc-blende CrTe and VTe have been performed. Zinc-blende CrTe and VTe at their equilibrium lattice constants are half-metallic with spin-down energy gaps of 2.82 and 2.70eV and half-metallic gaps of 0.89 and 0.33eV, respectively. The electronic structure of zinc-blende CrTe and VTe have been calculated under uniform strains from -10% to ＋10% relative to the equilibrium lattice constant. The calculated results indicate that zinc-blende CrTe and VTe can maintain half-metallic property and keep their total magnetic moments of 4.00 and 3.00 μB/formula for the uniform strains change within -6% ― 10% and -3% ― 10%, respectively. The zinc-blende CrTe and VTe retain half-metallic ferromagnetism from -6% to 10% and from -3% to 10% uniform strain, respectively.