Density functional calculations on 13-atom Pd12M （M= Sc-Ni） bimetallic clusters

The geometric structures,electronic and magnetic properties of the 3d transition metal doped clusters Pd12M(M=Sc-Ni) are studied using the semi-core pseudopots density functional theory.The groundstate geometric structure of the Pd12M cluster is probably of pseudoicosahedron.The Ih-Pd12M cluster has the most thermodynamic stability in five different symmetric isomers.The energy gap shows that Pd12M cluster is partly metallic.Both the absolutely predominant metal bond and very weak covalent bond might exist in the Pd12M cluster.The magnetic moment of Pd12M varies from 0 to 5 μB,implying that it has a potential application in new nanomaterials with tunable magnetic properties.     

玻色气体的磁性

物质磁性一直是凝聚态物理研究的重要课题.以往对磁性的探索主要是以费米子(局域或巡游的电子)为研究对象.由于传统的玻色系统液氦没有自旋,不表现磁性,玻色系统的磁性很少被关注.碱金属原子气体玻色-爱因斯坦凝聚的实现,在开辟了冷原子物理研究领域的同时,也打开了研究玻色系统磁性的大门.这是因为碱金属原子通常具有超精细结构,是旋量玻色气体,能够展示磁性.文章通过对比费米气体的相关结果,介绍了旋量玻色气体磁性的研究概况和最新进展,特别是铁磁性玻色气体的磁性相变以及在低温下铁磁性凝聚体的动力学特征.