Perpendicular Magnetic Anisotropy Caused by Interfacial Hybridization via Enhanced Orbital Moment inCo/PtMultilayers: Magnetic Circular X-Ray Dichroism Study

Abstract
Magnetic circular x-ray dichroism (MCXD) measurements at the Co L2,3 and M2,3 core edges reveal a strongly enhanced perpendicular Co orbital moment ( morb) in Co/Pt multilayers which show perpendicular magnetic anisotropy (PMA). MCXD signals at the Pt N6,7 and O2,3 edges, arising from Pt 5dCo3d hybridization, persist for the thinnest Co layer. The hybridization is shown to be localized at the Co/Pt interface and to cause the morb enhancement which drives PMA. Unambiguous evidence for a transition from fcc to hcp Co is presented and morb of bulk fcc Co has been determined to be 0.11μB for the first time.