MAGNETIC DICHROISM EFFECT OF BINARY-ALLOYS USING A CIRCULARLY-POLARIZED X-RAY

We have studied the magnetic properties of CoNi binary alloy films wit h various atomic compositions using the soft x-ray magnetic circular d ichroism technique. The alloy films were deposited on a single Cu(100) crystal in situ using our well established epitaxial growth technique to achieve a layer-by-layer growth and a metastable face-centered-cub ic structure, with all the films exhibiting an in-plane magnetic aniso tropy. The high density, circularly polarized x-ray beam was supplied by the elliptically polarizing undulator at the Stanford Synchrotron R adiation Laboratory. Utilizing the element-specific ability and nanost ructure magnetization sensitivity of this technique, we were able to p erform the absorption measurements at L-2 and L-3 edges of Co and Ni a toms and we observed large dichroism signals. The extraction of spin m oment and orbital moment for varying elemental stoichiometry using mag neo-optical sum rules is discussed. (C) 1997 American Vacuum Society.