Element-specific magnetic hysteresis as a means for studying heteromagnetic multilayers

We report element-specific magnetic hysteresis measurements on heteromagnetic materials. Dramatically different Fe and Co hysteresis curves of Fe/Cu/Co trilayers were obtained by recording the magnetic circular dichroism at their respective ${\mathit{L}}_3$ white lines as a function of applied magnetic field. The data resolve the complicated hysteresis curves, observed by conventional magnetometry, and determine the individual magnetic moments for the Fe and Co layers. Fine hysteresis features, imperceptible in the conventional curves, were also observed, demonstrating a new and powerful means for studying heteromagnetic multilayer systems.