简单金属小团簇Al_n(n=2～7)的磁性

Magnetism of Small-sized Al_n Clusters(n=2～7)

使用自旋极化的密度泛函理论下的第一原理方法,对简单金属铝的小团簇Aln(n=2～7)的结构特性和磁性进行了理论计算.结果表明:团簇的结合能随着团簇中原子数的增加而增大;虽然Al是简单金属,但是其小团簇Aln(n=2～7)具有磁性,磁矩在1μB和2μB间变化;通过能级图分析了Aln团簇磁矩的变化规律.此外,还分析了Aln团簇的磁矩、结合能、能量的一阶和二阶差分随原子数n的变化,讨论了最稳定团簇Al5的电子结构和电荷密度.

The structural properties and magnetism of Aln small clusters （n= 2～7） were studied by employing the first-principles calculations based on the spin-polarized density functional theory. The calculation results showed that., the binding energies increased with the number of atoms in the Aln clusters, although Al was a simple metal, the small-sized Aln clusters （n=2 ～ 7） could exhibit magnetism,with the magnetic moments changing between 1 μB and 2 μB. From the plot of energy levels, the magnetic moments of spin-polarized Aln clusters were discussed. Furthermore, the magnetic moment, the binding energy, the first and second differences of binding energies versus the number of atoms in the clusters were analyzed. The electronic structure and charge density of the most stable cluster Al5 were also discussed.