Atom movement and binding on surface clusters: Pt on Pt(111) clusters
Atom movement and binding on surface clusters: Pt on Pt(111) clusters
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DOI：
10.1103/physrevlett.77.1334
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发表时间：
1996-08-12
影响因子：
8.6
通讯作者：
Ehrlich, G
中科院分区：
文献类型：
--
作者：
Golzhauser, A;Ehrlich, G
利用氦冷却场离子显微镜研究了铂（111）上铂团簇上单个铂原子的结合和扩散。在温度接近20k时，在fcc和hcp位点均发现了沉积在Pt（111）团簇上的Pt原子。在hcp位点，原子的束缚更弱；在低至45 K的温度下退火后，它们完全占据fcc位点。然而，星团表面本身并不均匀。一个空区将中心区域与星团边缘分开：中心的原子必须克服能量障碍才能穿过这个空区并到达星团边缘。
Binding and diffusion of single platinum atoms adsorbed on platinum clusters on Pt(111) have been explored using helium-cooled field ion microscopy. Pt atoms deposited on Pt(111) clusters at T similar to 20 K are found at both fcc and hcp sites. At hcp sites, atoms are more weakly bound; after annealing at temperatures as low as 45 K, they occupy fcc sites exclusively. The cluster surface itself is not uniform, however. An empty zone separates the central region from the cluster edges: Atoms in the center have to overcome an energy barrier just to cross this empty zone and reach the cluster edges.