The kinetics of the interdiffusion of Co adatoms on a (111) surface were studied, by means of Auger electron spectroscopy at various temperatures, for Co coverages which were near to 1 monolayer. It was found that, after annealing, the Co concentration decreased markedly before approaching a constant value. It was noted that Co-Pt alloy formation was confined to a few uppermost layers. The activation energy and pre-exponential factor were obtained from an Arrhenius plot, and were equal to 0.90eV and 6.6 x 10-11cm2/s. These values were independent of the coverage in this ultra-thin system. After annealing 1-monolayer Co ultra-thin films on the (111) surface at 600K, Co atoms diffused into only the first 2 monolayers. Both the uppermost and second layers contained 50%Co.

J.S.Tsay, C.S.Shern: Journal of Applied Physics, 1996, 80[7], 3777-81