Li Jian-rong, Wang Guang-hou, Yao Chang-hong, Mu Yue-wen, Wan Jian-guo, Han Min
Department of Physics and National Laboratory of Solid State Microstructures, Nanjing University, Nanjing 210093, People's Republic of China.
J Chem Phys. 2009 Apr 28;130(16):164514. doi: 10.1063/1.3123805.
The structure, electronic, magnetic properties of Si(n)Mn clusters up to n=15 are systematically investigated using the density functional theory within the generalized gradient approximation. In the most stable configurations of Si(n)Mn clusters, the equilibrium site of Mn atom gradually moves from convex, to a surface, and to a concave site as the number of Si atoms varying from 1 to 15. Starting from n=11, the Mn atom completely falls into the center of the Si outer frame, forming Mn-encapsulated Si cages. Maximum peaks of second-order energy difference are found at n=6, 8, 10, and 12, indicating that these clusters possess relatively higher stability. The electronic structures and magnetic properties of Si(n)Mn clusters are discussed. The magnetic moment of Si(n)Mn clusters mainly is located on Mn atom. The 3d electrons in Mn atom play a dominant role in the determination of the magnetism of Mn atom in Si(n)Mn clusters. Furthermore, the moment of Mn atom in Si(n)Mn clusters exhibits oscillatory behavior and are quenched at n>7 except for n=12, mainly due to the charge transfer, strong hybridization between Mn 4s, 3d, 4p and Si 3s, 3p states.
采用广义梯度近似下的密度泛函理论，系统研究了n≤15的Si(n)Mn团簇的结构、电子和磁性。在Si(n)Mn团簇最稳定的构型中，随着Si原子数从1变化到15，Mn原子的平衡位置逐渐从凸位移动到表面位，再到凹位。从n = 11开始，Mn原子完全落入Si外框架的中心，形成Mn包裹的Si笼。在n = 6、8、10和12处发现二阶能量差的最大值，表明这些团簇具有相对较高的稳定性。讨论了Si(n)Mn团簇的电子结构和磁性。Si(n)Mn团簇的磁矩主要位于Mn原子上。Mn原子中的3d电子在决定Si(n)Mn团簇中Mn原子的磁性方面起主导作用。此外，Si(n)Mn团簇中Mn原子的磁矩表现出振荡行为，除n = 12外，在n>7时被淬灭，这主要是由于电荷转移、Mn 4s、3d、4p与Si 3s、3p态之间的强杂化作用。
