CORE-LEVEL MAGNETIC CIRCULAR-DICHROISM IN CO PT MULTILAYERS WITH VARYING CO-LAYER THICKNESSES/

Magnetic circular dichroism (MCD) has been studied on Co/Pt multilayer s at and around the Co M(2,3) and Pt N-6,N-7 and O-2,O-3 core-absorpti on edges using; directly characterized circularly polarized undulator radiation. The thickness of the Co layer(t(Co)) was varied between 3 - 14 Angstrom, with an almost constant Pt-layer thickness. We have also measured the reflectivity spectra down to 4eV and have made Kramers-K ronig analyses to obtain the dielectric tenser. The orbital magnetic m oment of Co is enhanced for samples with thinner Co layers. Magnetic m oments are induced on Pt atoms and ferromagnetically coupled with thos e on Co atoms. The Co M2,3 MCD for samples with perpendicular magnetic anisotropy(t(Co) < 7 Angstrom) is markedly different from that for sa mples with in-plane magnetic anisotropy(t(Co) > 7 Angstrom).