Calculated magnetic properties of an Fe1-xNix monolayer on Cu(001)

We present a detailed investigation of the magnetic properties of a single monolayer of Fe-Ni alloy film on Cu(001) substrate by means of the spin-polarized linear muffin-tin orbitals Green's-function technique and the Korringa-Kohn-Rostoker Green's function method. The coherent-potential approximation formalism is used in both approaches. Our study shows that the FeNi film remains in a high-spin state for the whole concentration interval, which agrees with experimental data. We observe substantial deviations between the film and the bulk magnetization in Fe-rich, as well as in Ni-rich alloys. We consider the influence of main important factors on the behavior of the magnetic moment of the film: (i) the nonequilibrium lattice parameter of the alloy, (ii) the interaction between the epitaxial monolayer of FeNi with substrate, (iii) reduced dimensionality of monolayers. The possibility of a direct extrapolation of results of surface properties towards properties of bulk alloys is discussed. [S0163-1829(99)14821-5].