Cs cluster binding to a GaAs surface

作者：Michael Krauss, Walter J. Stevens · 发表于：The Journal of Chemical Physics · 年份：1990 · DOI：10.1063/1.459230 · 被引用次数：12 · 研究领域：Advanced Chemical Physics Studies、Atomic and Molecular Physics、Electron and X-Ray Spectroscopy Techniques

A cluster model for the binding of Cs atoms on the (110) surface of GaAs is examined for polarization, charge transfer, and dispersion interactions. Binding energies for two or three atom clusters on GaAs are calculated to be less than 0.1 eV per Cs atom indicating only small binding contributions from charge transfer and polarization. Orbital and total charge density plots reveal an alkali valence charge weakly bonded between the alkali atoms and polarized toward the Ga atom. A London analysis of the dispersion energy between quasilinear Cs clusters and GaAs clusters finds it is large compared to the difference in stability between polyhedral clusters and the quasilinear clusters that are experimentally observed on the GaAs surface. The large dispersion energy is due to the large polarizabilities for quasilinear chains of Cs atoms whose longitudinal component increases approximately with the square of the chain length.