MAGNETIC-PROPERTIES OF CO/PT-MULTILAYERS

The magnetic properties of (111)-textured Co/Pt-multilayers have been studied theoretically by means of spin-polarized LMTO-band-structure calculations. In contrast to the interpretation of earlier experimental investigations, the Pt-layers have been found to be significantly magnetized by the adjacent Co-layers. This finding ensures that the Co-layers are exchange-coupled even for relatively thick Pt-interlayers. To get some information on the consequences of interface mixing we have used the ASA-version of the spin-polarized relativistic KKR-method of band-structure calculation to investigate the electronic and magnetic properties of Pt-(Co)-impurities in the various layers of the Co/Pt-multilayers. Our non-self-consistent results indicate that for most cases a slight increase in the magnetic moments has to be expected. To study experimentally the magnetic properties of the Pt-layers of vapor-deposited samples we have made use of the magnetic dichroism in X-ray absorption. This new technique allows to probe the Pt-layers separately and to estimate the average moment of this subsystem. While the estimated moments are in all cases somewhat higher than our corresponding theoretical results, their dependence on the Pt-layer thickness is in very satisfying agreement with the theoretical predictions.