Half-Heusler合金NiMn_(1-x)Nb_xSb的磁性和半金属稳定性

Magnetism and half-metallic stability of Half-Heusler compound NiMn_(1-x)Nb_xSb

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NiMn_1-_xNb_xSb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S1ater-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.

Based on the firstprinciples calculations within the density functional theory （DFT）, we systemeticly analyzed the electronic structure, magnetism and halfmetallic stability of halfHeusler compound NiMnNbSb. The results showed that the lattice constants and magnetic characteristics of the compound matched the Vegard law and the SlaterPauling rule well. The most stable halfmetallicity occurs at doping concentration z0.25 due to the Fermi level is situated the middle of the spindown gap. Furthermore, the present study also indicates that the hybridization of delectrons in NiMn and NiNb, which depend on RKKYtype inderect exchange mechanism, plays a dominating role in deter mining the magnetism.