Elastic electron backscattering from overlayer/substrate systems

Elastic electron backscattering probability for Au overlayers deposited on Ni were determined experimentally in the energy range 200-1000 eV. These me asurements were accompanied by characterization of the overlayer structure and the mean overlayer thickness. The elastic backscattering probabilities also were derived from extensive Monte Carlo simulations of the electron tr ansport in overlayer/substrate systems. Two overlayer structures were consi dered in these calculations: a uniform Au layer, and isolated Au islands lo cated on the uncovered substrate. Analysis of the shape of Au 4d spectra wi th QUASES-Tougaard software indicated that the latter structure is more pro bable. It has been found that the experimental elastic backscattering proba bilities compare better with the theoretical probabilities calculated for t he island structure. The possibility of characterization of the overlayer t hickness and structure from the elastic backscattering probabilities has be en discussed. Copyright (C) 2001 John Wiley & Sons, Ltd.