Electronic structure and magnetocrystalline anisotropy in Fe-Co-Ni binary alloy monolayers on Cu(0Â 0Â 1)

The electronic structures and magnetocrystalline anisotropy (MCA) energies of Fe-Co-Ni binary alloy monolayers on Cu(0 0 1) substrate under structural optimization have been investigated using the generalized gradient approximation. Isolated Fe-Co-Ni alloy monolayers are also studied for comparison. It is found that there exists a Slater-Pauling curve for the averaged magnetic moment of these alloying monolayers, whereas no such curve was found for the MCA energies. In addition to the perpendicular magnetization obtained for pure Fe and in-plane magnetization obtained for pure Co and Ni monolayers, a spin-reorientation transition upon a variation of the Fe concentration is observed in Fe-Co and Fe-Ni systems.