Ab-initio study of electronic and vibrational states of metal microclusters

由于金属微团簇比块体具有更大的表面积，因此它们被认为具有特殊的性质，包括磁性。最近，实验研究已经取得了进展，成功地控制这些集群的大小。本研究的目的是详细分析金属微团簇及其聚集体的电子态和振动态，我们首先研究了Ti_8C_2<12>金属微团簇的生长过程，它具有笼状结构，表面有五角形元素。与已知的富勒烯相比，我们应用紧束缚方案发现，在这种情况下没有形成大的笼，较大的团簇是<12>Ti_8C_2金属微团簇单元的组合。本文的DVM计算结果与10原子团簇下10 μ B的实验结果相符。还研究了Ni中Rh的嵌入簇，以提供与裸情况相比更高的磁矩。

Since metallic microclusters have large surface proportion compared to bulk, they are expected to have specific properties icluding magnetic properties. Recently, experimetal studies have progressed to be sucessful to control the sizes of these clusters. The present study aims to analyze in detail the electronic and vibrational states of the metallic microclusters and their aggregates.The first example we have studies was the growth process of the Ti_8C_<12> metallic microcluster, which has a cage like structure with pentagonal elements on the surface. Compared with the well-known fullerenes, we applied tight-binging scheme to find out that no large cages formed for this case and the larger clusters are the combimations of the unit of Ti_8C_<12> metallic microclusters.The next example is the Rh microcluters, which has magnetic moments, although the bulk Rh is nonmagnetic. The present DVM calculation reprodeced the experimental findings of 10 mu B at 10 atom cluter. Embedded cluters of Rh in Ni have also studied to give higher magnetic moments compared to the bare cases.