【摘要】 采用基于密度泛函理论的第一性原理方法系统研究了Au与3d过渡元素构成的混合小团簇的结构、稳定性、电子结构及磁性,得到了Au与3d过渡元素构成的混合小团簇的稳定结构.计算结果表明,Au与3d元素可形成大量的低能异构体,特别是有些异构体在结构上极相近,这不同于共价或离子键类型的团簇.与纯过渡金属团簇类似,这类团簇也表现出复杂的磁性.过渡金属元素的磁矩相比体材料而言既有增强的、也有减弱的,与轨道的交换劈裂密切相关.对于基态构型,AuCr2,Au2Cr2,Au2Mn2团簇中的两过渡金属元素的磁矩是反平行的,其他团簇为平行排列.异构体中过渡金属元素的磁矩也存在反平行排列的情形.更多还原

【Abstract】 The geometrical structure,stability,electronic structure and magnetism of bimetallic clusters AuM₂ and Au₂M₂,where M is 3d transition metal element,are investigated systematically by using the first-principles method based on density functional theory.In contrast to semiconductor clusters,the bimetallic clusters consisting of Au and transition metal elements usually form a large number of low-energy isomers,some of which are very similar in structure.Similar to the pure transition metal cluster,AuM₂ and Au₂M₂ clusters also display dramatic magnetism.The magnetic moment of transition metal element in AuM₂ and Au₂M₂ clusters is either enhanced or weakened with respect to the bulk value,which is closely dependent on the orbital splitting.For the ground state,the magnetic moments of two transition metal elements in AuCr₂,Au₂Cr₂ and Au₂Mn₂ clusters are anti-parallel,and those in other clusters are parallel.更多还原