The theory of metal-non-metal transitions in gold alkali liquid alloys

Abstract

By incorporating calculated liquid pair correlation functions into a tight binding Cayley tree model for the electronic structure of binary alloys, the authors have developed a self-consistent theory of the electronic and atomic structure of liquid alloys. Model calculations for the Au alkali systems show the existence of a gap in the density of states if the ratio of the electronegativity difference to the mean overlap integral exceeds a certain value. For alloys exhibiting a gap, a metal-non-metal transition occurs for concentrations in the neighbourhood of stoichiometry. This metal-non-metal transition occurs for values of the atomic parameters lying between those of Au-K and Au-Rb, in agreement with experimental findings. The transition is shown to be very sharp due to electron-electron interaction effects.