A theory of the electronic structure in metallic spin-glass alloys: AgcMn1-c

Abstract

The authors present a first-principles description of the electronic structure in metallic spin-glass alloys. The method is illustrated by explicit calculations for the AgcMn1-c system. In this case it consists of a Korringa-Kohn-Rostoker coherent potential approximation (KKR CPA) calculation for a three-component alloy. Namely, the lattice sites are taken to be occupied by Ag atoms with probability c, Mn atoms with local moments pointing 'up', Mn up arrow , with probability 1/2(1-c) and Mn atoms with the opposite orientation, Mn down arrow , with the same probability 1/2(1-c). They find that the Mn impurity band is exchange split, as in spin-polarised band theory with aligned spins, and the resulting gain in energy supports the moments. In this sense their theory is a generalisation of the Anderson model of impurity moment formation to finite concentrations. They study the density of states, Bloch spectral functions and the Fermi surface.