Electronic and magnetic properties of disordered AuCr alloys: A first-principles study

In this communication we have studied the electronic structure and magnetism in the disordered alloy AuCr, for compositions in which the Cr concentration is less than 30 at%. The study is an application of a first principles density functional based augmented space recursion technique generalized to study non-collinear magnetic structures. We showed that, at low temperatures but compositions with <15 at% Cr there is a spin-glass phase and the 1Q anti-ferromagnetic ordering stable above compositions of 15 at% Cr. We used the Lichtenstein procedure to map the problem onto a random Ising model and studied the phase diagram using a formalism suggested by one of us earlier. Our results are in excellent agreement with existing experimental data.