Surface diffusion and adatom‐induced substrate relaxations of Pt, Pd, and Ni atoms on Pt(001)

Abstract

Field ion microscope observations show that Pt atoms diffuse on Pt(001) by an adatom-substrate atom replacement mechanism, whereas Pd atoms diffuse on the same surface by site-to-site hopping. Ni adatoms are observed to exchange with substrate Pt(001) atoms at temperatures lower than the onset of their migration. The propensity for adatom-substrate atom exchange is found to be correlated with the amount of adatom-induced substrate relaxation. These relaxations are determined from calculations based on the embedded atom method.