Ni5Nd2B4的电子结构和磁性能研究  

The study of electronic structure and magnetism of Ni_5Nd_2B_4

作　　者：易勇[1,2] 丁志杰[1,2] 李恺[3] 易早[2,4] 唐永建[2] 罗江山[2] 

机构地区：[1]西南科技大学材料科学与工程学院,绵阳621010 [2]中国工程物理研究院激光聚变研究中心,绵阳621900 [3]中国工程物理研究院,激光聚变研究中心绵阳621900 [4]中南大学物理科学与技术学院,长沙410083

出　　处：《原子与分子物理学报》2011年第4期731-736,共6页Journal of Atomic and Molecular Physics

基　　金：国家自然基金(10476024)

摘　　要：采用LSDA(Local spin-density approximation)近似及LSDA+U(在位库伦势)近似模拟金属间化合物Ni_5Nd_2B_4的磁性能对于R—M—B合金特性的研究具有重要意义.研究结果显示,LSDA近似下,Ni_5Nd_2B_4具备金属导体性质,晶体结构中最紧邻Ni、B原子间杂化成键,最紧邻Ni—Ni共价成键,Nd、B原子形成成键分子轨道作用,Ni原子间存在自旋消弱现象;LSDA+U近似下,Nd原子磁矩提供体系磁性来源,由于自旋排斥作用Ni原子电子与Nd原子电子自旋方向相反,体系在U值约为6.35eV的作用下能较理想的处理体系电子作用.The simulation studies magnetic properties of the compound Ni5Nd2B4 within the local spindensity approximation （LSDA） and the LSDA＋U approximation, this is important to the study of R- M-B alloy characteristics. The simulation results show that, this system is a metallic conductor within LSDA approximation, the neighboring Ni and B atoms form hybridized orbit, the covalent bond exists in Ni-Ni, the Nd and B form bonding molecular orbital, the phenomenon of the spin weakening is existence between Ni atoms; within LSDA＋U approximation, the total magnetic moment is provided by the local Nd magnetic moment, the Ni and Nd electronic spin direction is opposite by the spin exclusion effect, the system electronic role can be described when coulomb U is 6.35 eV.

关 键 词：密度泛函理论 电子键结构 磁性能 稀土过渡金属间化合物 

分 类 号：TQ050.4[化学工程] O482.5[理学—固体物理]