Abstract
In this study, the influence of Ag buffer layer on magnetic properties of ultra-thin Co/Ag/Ge(111) films was focused.A series of ultra-thin Co films on Ag/Ge(111) in UHV system was grown and analyses were done on the surface magnetic properties with low energy electron diffraction (LEED), Auger electron spectrometer (AES) and in-situ surface magneto-optic Kerr effect (SMOKE) techniques. Also included are the growth of the ultra-thin films, the research of the surface structure and magnetic properties of the as-grown and annealed films.Ag buffer layer was found to efficiently prevent the formation of cobalt germanide. Therefore, the number of non-ferromagnetic dead layers at the Co/Ge interface can be reduced by the Ag buffer layer. As the growth temperature increases, thicker Ag coverage is required to avoid the formation of germanide due to stronger thermal motion at higher temperatures. On the other hand, Co/Ag/Ge shows smaller coercive force due to smaller interfacial stresses.The samples were continuously annealed in-situ, the hysteresis loops recorded based on the polar configuration was observed due to the formation of Co-Ag granular films.