Intermixing during growth of Cr on Fe(100) studied by proton- and electron-induced Auger-electron spectroscopy.

Abstract

1- and 2-ML Cr films have been grown on Fe(100) under layer-by-layer conditions and studied using Auger electron spectroscopy induced by electrons and grazingly incident protons. Exploiting the different sampling depths for proton and electron excitation, we could quantitatively evaluate the layer-dependent concentration profiles of Cr and Fe near the film surface and their evolution in time. For a coverage of 1 ML, more than half of the deposited Cr atoms have undergone place exchange with Fe substrate atoms, which results in a mixed first and second layer. For 2 ML, the first and second layer consist predominantly of Cr. Long-time measurements show that as-grown 1-ML films are not stable. \textcopyright{} 1996 The American Physical Society.