BINDING SURFACES AND STRUCTURAL PHASE-TRANSFORMATIONS

We have calculated binding surfaces for cia changes (along the Bain pa th) and changes of the atomic volume of metallic systems undergoing ma rtensitic transformations. We find characteristic differences between the surfaces of nonmagnetic systems (with a close packed low temperatu re structure) and magnetic systems (with a less close packed low tempe rature structure). The ab initio calculations have been performed by u sing the augmented-spherical-wave method within the local-density appr oximation in the case of stoichiometrically ordered compounds and the Korringa-Kohn-Rostocker method together with the coherent-potential ap proximation in the case of disordered alloys.