Cobalt ultra-thin film epitaxy on Pt(100) surfaces

Abstract

To test the possibility of obtaining good Co-Pt multilayers, we studied the initial stages of growth of Co on Pt(100) by surface physics techniques in order to determine the structural order of ultra-thin Co layers. The LEED-Auger data for room temperature deposition can be explained by a quasi layer-by-layer growth showing a large surface disorder. Photoemission experiments using the synchrotron radiation in the 40–130 eV range confirmed that the interface is not really abrupt and evidenced a limited interdiffusion process below the cobalt overlayers.Annealing these cobalt ultra-thin films (2–10 ML) in the 200–400 °C range gave rise to a progressive epitaxy of a cubic phase on platinum, clearly identified by LEED and RHEED. This showed the possibility of building in this temperature range an interface structurally better defined than at room temperature.