Two-dimensional Mn–Co surface alloy on Co(0 0 1)

Surface alloy formation of Mn on Co(0 0 1) was detected by low-energy electron diffraction and in situ magneto-optic Kerr effect experiments. Here we discuss the electronic and magnetic properties of an equivalent Mn monolayer (ML) at the surface of Co(0 0 1) using the tight-binding linear muffin-tin orbitals method. Magnetic configurations and stability of ordered 2D Mn–Co alloy 2 ML thick vs Mn/Co(0 0 1) and Co/Mn/Co(0 0 1) have been considered. Multiple magnetic configurations have been always obtained but a comparison between the ground states display an instability of the perfect Mn ML on Co(0 0 1). Total energy differences are considerably reduced in the case of spin-polarization calculations as compared with the non-magnetic one.