Magnetic moment in the top Pt layer of Co/Pt bilayers

The magnetic properties of a few atomic Pt layers on a 15nm thick Co film were studied by x-ray magnetic circular dichroism spectroscopy at the Pt L 2,3 edges. The spin and orbital magnetic moments of the Pt 5d electrons were separated using the magneto-optical sum rules. The Pt magnetization profile as a function of distance from the Co-Pt interface was determined using data from a series of films with various Pt thicknesses. This magnetization profile was approximated by an exponential function with a decay length of 0.41nm, which characterizes the effective range of the magnetic coupling between Co and Pt. The total magnetic moment of a Pt atom at the interface was 0.7μB/atom including a 13% orbital moment. This is discussed in the context of the thermal stability of magnetic recording media capped with a thin layer of Pt. © Physica Scripta 2005.