Magnetic exchange coupling of Co/Ir multilayers

We present ab initio calculations of the exchange coupling for Co/Ir systems using a self-consistent full-potential linearized augmented plane-wave (FLAPW) method. The local spin density approximation (LSDA) as well as the generalized gradient approximation of (GGA) are used to treat the exchange correlation potential. Structural optimization is considered for all systems due to the size difference between Co and Ir atoms. We obtain an oscillatory behavior for the interlayer exchange coupling with a period of 5.83 Å, for both LSDA as well as GGA-PBE. The first antiferromagnetic peak is found for an Ir spacer of thickness 3.74 Å, with strength of J=51.09 mJ/m<Superscript>2</Superscript> for the GGA-PBE and 37.00 mJ/m<Superscript>2</Superscript> for the LSDA. Copyright EDP Sciences/Società Italiana di Fisica/Springer-Verlag 2008