Electronic structure modification induced by ion irradiation during film growth of Cu and Pd

Abstract

Cu and Pd thin films grown under particular conditions of ion irradiation exhibit a lattice spacing expansion and a high density of lattice defects. As a consequence of this crystallographic disorder the Fermi edge of these systems is located at a higher binding energy, while the electronic core levels are broadened and shifted upward ≊0.35 eV, as shown by x-ray photoelectron spectroscopy measurements. This letter demonstrates that the electronic structure modifications observed in these materials can be accounted for on the basis of the measured lattice parameter and lattice disorder invoking an energy band structure model for fcc metals and self-consistent field wave function computations.