Reaction of thin Pd films with Al(111) and Al(110) surfaces

Abstract

High-resolution ion backscattering has been used to study the reaction of thin Pd layers with Al(111) and Al(110) surfaces. The measurements show that alloy formation occurs at the surface for a range of Pd coverages from 0 to 7 × ${10}^{15}$ atoms/${\mathrm{cm}}^2$. The results are discussed in terms of a reaction model in which each Pd atom effectively displaces one Al substrate atom, with an additional two monolayers of disordered Al at the interface. A Pd film ultimately grows on the reacted layer, expitaxially ordered in the case of the Al(111) surface.