Theoretical Models for Adsorption and Diffusion of In on Cu(100)

Abstract

Using ab-initio molecular cluster calculations we show that In adsorbed on Cu(100) surface occupies a position above the bridge sites of the Cu plane and that the electric field gradient felt by the In atoms is appreciable only at Cu vacancies. To explain data from PAC experiments we propose that the radioactive In probes diffuse to the Cu plane during the decontamination process. Monte Carlo simulations of the In cluster kinetics show this model to be feasible and also that the free In monomer hopping rate is about 30 times greater than previous estimates.