Fen／Crn超晶格磁性和电子结构的第一性原理研究

First Principle Study of Magnetism and Electronic Structure of Fe_n/Cr_n Superlattices

采用基于密度泛函原理的全势线性缀加平面波方法(FLAPW),计算了超晶格Fen/Crn(n=1,3,5)的电子结构和磁性,结果表明铁磁耦合状态是基态,铁层的磁矩由于铬层的加入而有一些变化,铁层的磁矩随着n的增大而逐渐增强.铬层的磁矩的方向是正负相间变化的,相邻的铁层和铬层之间是反铁磁性耦合的,铁原子的d轨道和铬原子的d轨道在费米能附近有中等程度的杂化.

Electronic structure and magnetism of Fe,,/Cr,, superlattices（SL） with various layer thickness （n = 1,3,5） are studied using a full-potential linearized augmented plan-wave（FLAPW） method within a density functional formalism. It is shown that ferromagnetic state is a preferable phase in the ground state and the intrinsic spin density wave length is about 2 monolayers （ ML）. The magnetic moment of Fe layer is slightly modified by an intelvening Cr layer, and becomes stronger with the increase of n. The direction of Cr magnetic moment alternates layer by layer. An antiferromagnetic coupling hetween interfacial Fe and Cr layers is observed. There is a moderate hybridization between d-states of Fe and Cr atoms near Fermi energy.