MAl_(12)(M=Ni、Mn)及其阴离子团簇的几何结构和磁性的计算研究  

Geometric structures, electronic and magnetic properties of MAl_(12)(M=Ni,Mn)and their anions clusters

作　　者：柏于杰[1] 孙厚谦[1] 成海英[1] 罗改霞[1] 王保林[1] 邓开明[2] 

机构地区：[1]盐城工学院基础教学部,盐城224051 [2]南京理工大学应用物理系,南京210094

出　　处：《原子与分子物理学报》2010年第6期1081-1086,共6页Journal of Atomic and Molecular Physics

基　　金：国家自然科学基金(10874025);盐城工学院自然科学研究基金(XKY2009053)

摘　　要：采用密度泛函理论(density functional theory,DFT)中的广义梯度近似(generalized gradient approximation,GGA)分别对Al_(13)和MAl_(12)(M=Ni、Mn)四种初始结构的中性和一价阴离子团簇进行计算研究.发现中性和阴离子团簇的基态几何结构均保持I_h对称性,并且基态阴离子团簇还具有较高的运动学稳定性.电磁性质计算显示:基态的中性和阴离子NiAl_(12)团簇分别带有2_(μB)、3_(μB)的磁矩,Ni原子的磁性几乎完全淬灭;而MnAl_(12)团簇分别带有7_(μB)、6_(μB)的磁矩,Mn原子的磁矩主要由3d轨道提供.基态团簇的表面原子出现了自旋分裂,与中心原子呈现出铁磁性作用.对垂直电离能和垂直亲和能的分析表明:中心原子被替代之后,团簇的得电子能力和失电子能力都有所降低.The four types of origi clusters have been studied using t ry. It was found that the ground nal structures for Alia ,MAl12 （M= Ni,Mn） with neutral and anionic he generalized gradient approximation based on density functional theostate structures of symmetry, and the ground state anionic clusters sti magnetism calculation shows that the ground states both the neutral and anionic clusters all keep in Ih 11 have comparatively higher kinetic stability. The of NiAl12 for neutral and anionic clusters have 2μB and 3μB magnetic moments respectively, but the magnetism of the Ni atom is almost extinguished. The ground states of MnAl12 for neutral and anionic clusters have 7μB and 6μB magnetic moments respectively. Furthermore the magnetic moments of Mn atom are mainly provided by the 3d orbit. The surface atoms of ground state clusters occur self-spin split, presenting the ferromagnetic arrangement with the center atom. It is found from the vertical ionization potential and the vertical affinity potential that the ability for both detaching and attaching electrons decreases after the substitution of the central atom.

关 键 词：几何结构 磁性 密度泛函 

分 类 号：O561[理学—原子与分子物理]