Short period oscillations in the Kerr effect of 4d- and 5d-transition metal wedges on Co films (invited) (abstract)

Abstract

We report a novel type of short period oscillations in electron-beam evaporated Co films covered with wedge-shaped films of Pt, Au, and Pd. Oscillatory behavior, with periods in the range 2–3 Å, is observed both in the saturation polar Kerr angle and in the high field susceptibility, as a function of the wedge position (see Fig. 1). The structures of the type buffer/Co/X wedge/Y cap were made by high vacuum evaporation using fused silica as substrates. They consist of a 200 Å Pt buffer layer, a thin Co layer revealing a perpendicular easy magnetization axis, a transition metal wedge (X) with thickness in the range 0–25 Å, and a thin Cu or Au cap (Y) layer. The presence of oscillations depends critically on the choice of the cap-layer Y. They are distinctly different from long and short range period oscillations observed in magnetic sandwich or multilayer structures, since there is only one magnetic film involved. The present results will be discussed in the framework of spin polarized quantum well states.