Ni基金属间化合物第一性原理研究

稀土(R)-过渡族(T)金属间化合物具有优异的物理和化学性质.本研究考虑电子自旋极化作用,基于第一性原理的全电子投影缀加平面波赝势法理论,采用局域自旋密度近似(LSDA),对Ni₁₃Nd₃B₂金属间化合物进行结构优化,计算体系晶格常数、电子结构和磁性能.结果表明,Ni₁₃Nd₃B₂为带隙很小的金属导体.LSDA近似下体系原子间存在复杂作用类型,Nd原子与近邻Ni,B原子以离子键作用为主,Ni原子与近邻Ni原子间表现共价作用情形.体系存在Nd-Ni铁磁耦合,总磁矩约8.4329μB,主要由Nd原子磁矩提供,自旋极化引起的体系Nd-4f,Ni-3p,Nd-5p电子自旋劈裂为体系表现磁性的根本原因.

First-principles study of Ni-based metal compound

The rare earth-transition (R-T) intermetallics has excellent physical and chemical properties. The electronic structure, the band structure and the magnetic properties of the compound Ni₁₃Nd₃B₂ are studied by using the first-principles plane wave pseudopotential method and the local spin-density approximation (LSDA). The calculation results indicate that this system is a metallic conductor with a very small band gap. The system has very complex bonding, where Nd atoms and the neighboring Ni and B atoms form ionic banding, whereas Ni atoms and the neighboring Ni atoms form covalent bonding. Under LSDA approximation, the system has Nd-Ni ferromagnetic coupling, and the total magnetic moment ( ≈ 8.4329μB) is provided by the local Nd magnetic moment. The Nd-4f, Ni-3p, Nd-5p electron spin splittings due to spin polarization result in the magnetic system.