Partial structures of compound-forming liquid gold-caesium alloy. A model potential approach

Abstract

The compound-forming AuCs alloy is studied with a square-well potential as a perturbation over a hard-sphere mixture. The partial structure factors S₁₁(k), S₁₂(k), S₂₂(k) and also S_NN(k), S_CC(k), and S_NC(k) are computed at various concentrations and temperatures. Here 1 refers to gold and 2 refers Cs. The total structure factors obtained by the present method agree very well with the measured values. The most important aspect of the computations is the accurate evaluation of the number density of each of the species. Density measurements indicate strong contraction at 50% concentration and it is found to give a subsidiary peak in S₁₁(k) and a high principal peak for S_NC(k) at this concentration. The present calculations show that if the correct density measurements and hence the number densities are available, the evaluation of partial structure factors with sufficient accuracy is possible. Also the present calculations show many similarities with the CuPb alloy which also forms a compound.