Abstract:
One-monolayer films of 3d-metals on the tungsten (001) surface are known to exhibit surprising magnetic behavior - V, Cr, and Mn monolayers are ferromagnetic, while Fe and Co tend to the c(2x2) antiferromagnetic ordering. We explore magnetic properties of two-dimensional binary alloys of the 3d-metals on W(001) in one monolayer and submonolayer coverage. We employed the tight binding linear muffin-tin orbital method (TB-LMTO) combined with the coherent potential approximation (CPA) to calculate the total energy and electronic structure for various magnetic configurations (e.g. ferromagnetic, antiferromagnetic, DLM) of the investigated systems. These calculations were supplemented by full-potential linearized augmented plane wave (FP-LAPW) calculations. The values of total energy were analyzed so as to find the trends in magnetic ordering as a function of composition. The magnetic moments of Cr, Mn, and Fe atoms in the two-dimensional alloys turn out to be rigid, while the magnetic moment of a vanadium atom is sensitive to the local environment of the atom. The most interesting result for the submonolayer films is the disappearance of their magnetic moments at low coverage for V and Cr. It will be shown that even for the submonolayer coverage the Stoner criterion may be useful.