Stacking fault energies of random metallic alloys

Abstract

Stacking fault energies in dilute Cu(Al) alloys and across the composition range of PdAg alloys are calculated from first principles using the layer Korringa-Kohn-Rostoker method and treating the compositional disorder within the coherent potential approximation. In Cu(Al), rigid-band behaviour results in a sharp reduction in the fault energy with Al concentration. The non-uniform variation of the fault energy in PdAg is understood in terms of the relative band-widths and d-resonance energies of Pd and Ag.