Coulomb correlations and magnetic anisotropy in orderedL10CoPt and FePt alloys

We present results of the magneto-crystalline anisotropy energy (MAE)\ncalculations for chemically ordered $L1_0$ CoPt and FePt alloys taking into\naccount the effects of strong electronic correlations and spin-orbit coupling.\nThe local spin density + Hubbard U approximation (LSDA+U) is shown to provide a\nconsistent picture of the magnetic ground state properties when intra-atomic\nCoulomb correlations are included for both 3$d$ and 5$d$ elements. Our results\ndemonstrate significant and complex contribution of correlation effects to\nlarge MAE of these material.\n