Fe_(6-x)Al_x团簇的结构和磁性能

Structures and Magnetic Properties of Fe_(6-x)Al_x Clusters

在密度泛函理论的BPW91水平上,对Fe6-xAlx团簇进行了结构优化,并将获得的最低能结构进行稳定性分析以及电子结构和磁性能的计算.计算结果表明,铁原子倾向团聚在一起并占据最高配位,Al原子则倾向分布在铁簇的周围尽最大可能地与Fe配位成键.Fe6-xAlx团簇的磁性随Al原子数目增加呈现下降趋势,自然轨道分析揭示Fe4s和Al3s与Fe3d之间的杂化是导致团簇磁矩下降的主要原因.

All possible geometrical structures of Fe6-xAlx clusters were optimized at the BPW91 level in density functional theory（DFT）.The stability and electronic structures as well as magnetic properties of the lowest-energy structures are analyzed.Theoretical results show that iron atoms are brought together,yielding a maximum of Fe—Fe bonds,and aluminum atoms are located around the Fe core with a maximum of Fe—Al bonds.As the number of Al atoms increases,the total magnetic moments of Fe6-xAlx clusters decrease.Natural bond orbital analysis reveals that the hybridization between Fe 4s,Al 3s and Fe 3d results in decreasing the total magnetic moments of Fe6-xAlx clusters.