Ni_4PrB的电子结构和磁性能研究

Study of Ni_4PrB electronic structure and magnetism

考虑Pr-4f及Ni-3d电子间的库仑作用U和交换作用J,采用局域自旋密度近似LSDA(Local spin-density approximation)及LSDA+U(在位库仑势)近似,对Ni4PrB化合物进行结构优化,并计算体系电子结构,能带结构和磁性能.结果显示,Ni4PrB具备金属半导体性质,存在Pr-Ni铁磁耦合.U的引入对体系磁特性和结构稳定性有关键作用,加U前体系磁性来源为Ni原子磁矩,加U后体系磁性来源为Pr原子,且体系稳定性提高,U值的作用对于修正体系强关联有重要影响,可以合理描述由强关联和自旋排斥引发的排斥效应.

Considering the Coulomb potential and the exchange action,electronic structure,band structure and magnetic properties of the compound Ni4PrB within the local spin-density approximation（LSDA） and the LSDA＋U approximation are studied through numerical simulation.The simulation results show that this system is a metallic semi-conductor and has Pr-Ni ferromagnetic coupling.The added Coulomb U effect can strongly affect magnetic properties and stable structure,and the total magnetic moment is provided by the local Ni magnetic moment before adding U effect,when the U effect is added to the system,the total magnetic moment is provided by the local Pr magnetic moment,and the system has a high structure stability.So U effect affects strongly the strong correlation,then it can describe reasonably the strong correlation and the exclusion effect caused by the spin exclusion.