Half-Heusler合金NiMn1-xNbxSb的磁性和半金属稳定性

基于密度泛函理论的第一性原理计算，我们系统地研究了half-Heusler合金NiMn1-xNbxSb的电子结构、磁性和半金属稳定性。结果表明合金的晶格常数和磁性分别很好地符合Vegard定理和Slater-Pauling规则；当掺杂浓度为25%时，合金的费米面恰好位于其自旋向下带隙的中部，从而呈现最稳定的半金属性。此外，当前的研究也显示Ni-Mn和Ni-Nb之间的d电子杂化依赖于RKKY间接交换机制，共同贡献于合金的总磁矩。

Magnetism and half-metallic stability of Half-Heusler compound NiMn1-xNbxSb

Based on the first-principles calculations within the density functional theory (DFT), we systemeticly analyzed the electronic structure, magnetism and half-metallic stability of half-Heusler compound NiMn1-xNbxSb. The results showed that the lattice constants and magnetic characteristics of the compound matched the Vegard law and the Slater-Pauling rule well. The most stable half-metallicity occurs at doping concentration x=0.25 due to the Fermi level is situated the middle of the spin-down gap. Furthermore, the present study also indicates that the hybridization of d-electrons in Ni-Mn and Ni-Nb, which depend on RKKY-type inderect exchange mechanism, plays a dominating role in determining the magnetism.