Rh_nAl(n=1～6)团簇结构和磁性的研究

Geometrical structures and magnetisms of Rh_nAl(n = 1-6) clusters

用密度泛函理论中的广义梯度近似方法研究了Rh_nAl(n=1～6)团簇的结构和磁性.结果表明:Rh(_n-1)Al和Rh_n(n=2～7)团簇结构是相似的,结合能随团簇尺寸变化趋势一致,原子间的s,p,d轨道杂化使得Rh_nAl团簇更加稳定.几乎所有Rh原子都是电子受体,Al-Rh键长越小.Rh原子得电子就越多.团簇磁矩主要来自Rh原子的贡献,Rh原子的4d轨道磁矩是Rh原子磁矩的主要部分.Al原子失去的电子越多,则其磁矩就相对越小.

Geometrical structures and magnetisms of RhnAl（n=1~6） clusters were studied by using generalized gradient approximation in the density functional theory. The result shows that the structures of Rhn-1Al clusters are similar as which of Rhn （n=2~7）clusters, and the lines of binding energy verse cluster size are also similar, but the structures of RhnAl clusters are more stable because s orbit, p orbit and d orbit hybrid of atoms in the clusters. Almost all Rh atoms receive electrons. The bond length of Al-Rh is shorter, Rh atom receives more electrons. Magnetic moments of RhnAl clusters are mainly due to Rh atoms, and magnetic moment of Rh atom is mainly due to 4d orbital magnetic moment of Rh atoms. Al atom losses more electrons, its magnetic moment is relatively smaller.