The magnetic properties of CoPt, bulk and ultra-thin films: An ab initio study

Magnetic CoPt nanoparticles in the ordered L10 phase have recently been fabricated primarily for use in high density data storage applications. In this study, the results of ab initio simulations of the L10 phase and ultra-thin films of CoPt using the generalised gradient approximation (GGA), pseudopotentials, a plane wave basis set and spin-orbit coupling are presented. Calculated structural parameters and magnetic moments for the bulk are in very good agreement with experimental results. The calculated structural parameters of ultra-thin films of CoPt are shown to vary little from that of the bulk but the magnetic moments for these thin films show a significant increase with decreasing film thickness.