Oscillatory behavior of coercivity in Bi/Co bilayers

Abstract The Bi/Co bilayers on the glass substrate with various thicknesses of Bi underlayer were prepared by DC sputtering method. A remarkable enhancement of the coercivity H c of sputtered thin Co films was observed. Besides, its coercivity at room temperature was found to oscillate as a function of Bi thickness with a period of about 22 nm. The range of oscillation was observed at least up to 80 nm. The origin of the oscillation in the coercivity of cobalt film was thought to arise from the specific 3D growing mechanism of bismuth layer.