Magnetic order of FeMn alloy on the W(0 0 1) surface

We theoretically investigate the ground state of the FeMn binary alloy monolayer on the W(0 0 1) surface, the stability of different magnetic configurations (ferro/antiferromagnetic, disordered local moments, etc.) and estimate concentrations at which a transition occurs between different magnetic orders. The tight-binding linear muffin-tin orbital method combined with the coherent potential approximation is used to treat the surface alloy appropriately. We discuss the role of disorder on the phase transitions in surface alloys composed from two different 3d transition metals.