Abstract
Multilayer films consisting of 70 at%Co-30 at%Ni alloy and Cr were prepared by DC magnetron sputtering. The number of (Co-Ni/Cr) stacks and the thickness ratio of Co-Ni and Cr layers were varied while the total Co-Ni thickness was maintained at 900Å. An appropriate combination of the number of stacks and the thickness ratio improves both coercive force and squareness ratio of the films wihout an appreciable decrease in saturation magnetization. The change in saturation magnetization can be explained in terms of interdiffusion near Co-Ni/Cr interfaces. The change in coercive force of multilayer films, the value of which is determined by that of the first two layers of Cr and Co-Ni, is controlled by the thickness of a Co-Ni layer.
