Growth of aluminum oxide thin films on Cobalt : An AES and AFM study

Auger Electron Spectroscopy (AES) and Atomic-Force-Microscopy (AFM) were used to study the formation and the surface roughness of a very thin aluminum oxide film deposited on Co substrate. The results show that the superficial oxide (AlOx) film on the surface of cobalt obtained after oxidation at room temperature (RT) of one aluminum monolayer (ML), is not stoichiometric alumina with an atomic structure similar to known phases. It shows a composition profile close to... /Co/Co/AI/O. This superficial oxide is very stable: there is no dissolution process of the film at least up to 500°C. The superficial oxide formation does not change the initial surface roughness of the cobalt.