Bright beaches of nanoscale potassium islands on graphite in STM imaging.
Bright beaches of nanoscale potassium islands on graphite in STM imaging.
复制标题
DOI：
10.1103/physrevlett.102.106102
复制
发表时间：
2009-03
影响因子：
8.6
通讯作者：
Feng Yin;J. Akola;Jaakko Akola;Pekka Koskinen;M. Manninen;Richard E. Palmer
中科院分区：
文献类型：
--
作者：
Feng Yin;J. Akola;Jaakko Akola;Pekka Koskinen;M. Manninen;Richard E. Palmer
我们证明，通过扫描隧道显微镜（STM）在48 K下进行的测量，存在的“亮滩”在石墨表面上的K岛（直径约5-500 nm）的边缘。增强的隧穿电流只观察到在单层高的岛屿石墨，而不是在类似的几何形状的K单层膜的顶部的岛屿。第一性原理密度泛函计算和STM模拟表明，这是一个STM场效应，这似乎是因为正尖端吸引捐赠的电子回到金属K岛。恢复的电荷优先积累在岛的边缘。
We demonstrate, via scanning tunneling microscopy (STM) measurements performed at 48 K, the existence of "bright beaches" at the edges of K islands (diameter approximately 5-500 nm) on the graphite surface. The enhanced tunneling current is only observed in monolayer-high islands on graphite, and not in islands of similar geometry on top of a K monolayer film. First-principles density functional calculations and STM simulations suggest that this is an STM field effect, which appears as the positive tip attracts donated electrons back to the metallic K islands. The restored charge accumulates preferentially at the island edges.