Experiments and simulations on Al-Au mixtures and mixtures laws

Abstract

We measured the thermodynamical and transport properties of aluminum-gold mixtures in the warm dense matter regime and for various concentrations. We compare these measurements with quantum molecular dynamics (QMD) simulations. We find that the calculated pressures and resistivities of both the mixtures and pure phases are in good agreement with the measurements. This further allows us to test the mixing rules usually employed to predict the properties of the mixed phases from the pure ones. We show, in this regime, that the partial densities mixing rule predicts the pressure of the mixture rather accurately but fails in its prediction of the optical conductivity. To improve this latter prediction, we find that we must invoke an isothermal-isobaric mixture rule to compute the pure phase contributions at the correct densities.