Comparative study in annealing effects of Ag/Co/Pt(111) and Co/Ag/Pt(111) ultrathin films

Low-energy electron diffraction (LEED), Auger electron spectroscopy and dep th profile were used to study the growth and annealing effects of mirror sy stems: Ag/Co/Pt(111) and Co/Ag/Pt(111). An anomalous behavior of specular b eam intensity of LEED versus temperature was found in the annealing process for Ag/Co/Pt(111). A dramatic increase of the beam intensity occurs after Co-Pt alloy formation is complete. The exchange between Co and Ag atoms of Co/Ag/Pt(111) occurs when the annealing temperature is high enough. The Co- Pt alloy develops after the atomic exchange is complete. The chemical compo sitions at the interfaces of these two ultrathin films were investigated. T he mechanisms of the different behaviors of the two systems in the annealin g processes are discussed. (C) 2001 Elsevier Science B.V. All rights reserv ed.