Palladium magnetism in Pd/Fe multilayers studied by x-ray magnetic circular dichroism at the Pd L2,3 edges (abstract)

Abstract

We have performed direct measurements of the Pd 4d orbital and spin moments in Pd/Fe multilayers with different Pd interlayer thicknesses, using x-ray magnetic circular dichroism (XMCD) at the L2,3 edges of Pd. The Pd/Fe multilayers were grown by molecular beam epitaxy on MgO (001) substrates and the XMCD experiments were performed on beamline 6 at the ESRF using fluorescence yield detection. We found that the Pd atoms directly at the interface are strongly polarized with a total moment of 0.4 μB/atom. The orbital moments are found to be small (0.0–0.04 μB). The hybridization of the Pd 4d states with the Fe 3d band leads to a small increase in the number of Pd 4d electrons, of about 0.1 electron per Pd atom. The thickness dependence of the XMCD shows that the Pd atoms are magnetically polarized up to four layers from the interface. From the spectral features observed after the L3 and L2 white lines we can also show that the structural Pd/Fe interface is smooth and that in the two atomic layers adjacent to Fe, the Pd atoms have a local structure imposed by the epitaxy on Fe which differs from face centered cubic. The relation between electronic structure and magnetic properties will be discussed.