TOWARD A UNIFIED APPROACH TO THE STUDY OF METALLIC ALLOYS - APPLICATION TO THE PHASE-STABILITY OF NI-PT

We present the first implementation of a unified approach to the study of alloys, using the atomic-sphere approximation formulation of the K orringa-Kohn-Rostoker coherent potential approximation method [P. P. S ingh and A. Gonis, Phys. Rev. B 48, 1989 (1993)], which allows the tre atment of the disordered alloy and of the ordered alloys on an equal f ooting. We apply this method to the study of the phase stability of th e Ni-Pt alloy and resolve a number of discrepancies that have arisen i n recent studies of this system.