The low-temperature electronic specific heats of disordered Ag-Au alloys, revisited

Disordered alloys of silver and gold have been in the interest of the condensed matter community for decades. Although they are considered well-known materials, surprises have appeared that have not been fully understood, e.g., experimental results of the electronic specific heat at low temperatures of disordered Ag-Au alloys. Green and Valladares (1966) conducted experimental studies of γ , the coefficient of the temperature in the expression for the electronic specific heat at low temperatures, finding a parabolic behavior as a function of the concentration. Several ulterior experiments corroborated this parabolic behavior, and theoretical attempts followed that did not satisfactorily succeed at the explanation. The parabolic behavior is reproduced in this computational work as a function of concentration. As a byproduct an estimation of the electron-mass renormalization due to the electron–phonon interaction was obtained for all concentrations, estimation that agrees with the limited number of experiments. • Silver and gold atoms are chemically similar but show local preferences when alloyed. • Properties of these alloys do not follow a linear behavior among their pure elements. • Electron–phonon interactions contribute to the low-T specific heats of these alloys. • Experimental results are favorably analyzed in the light of mature DFT-based methods.