Theoretical Study of the Stability of CdSn Liquid Alloy at Different Temperatures

The quasi-lattice theory (QLT) is utilized for the prediction of the temperature and concentration dependence of the thermodynamic properties of the molten CdSn alloys. At first, the analytical expressions are employed to reckon the excess Gibbs free energy of mixing, Gibbs free energy of mixing, activity, enthalpy of mixing and entropy of mixing as well as concentration fluctuations, short range-order parameter and excess stability function ofCdSn melts at 773 K. For this, the model parameters i.e. size ratio and order energy parameter are assessed using the experimental data of the free energy of mixing for CdSnmelts at 773 K. The theoretical values of the thermodynamic functions are in well harmony with the interrelated experimental values. The theoretical values of the structure function like concentration fluctuations are in unison with the experimental values for molten CdSn system at 773 K. Again, the optimization procedure is applied to explore the excess Gibbs free energy of mixing, activity, concentration fluctuations, short-range order parameter and excess stability function at different temperatures for CdSnmelts. The present study discloses that the stability as well as the segregating nature of CdSnmelts decrease with the elevation of the temperature from 773 K to 1123 K. Further, the temperature dependency of the excess stability function reveals that there is a probability of transition from segregating character to the ordering character of CdSn melts near 1162 K. Keywords: Gibbs free energy of mixing; entropy of mixing; concentration fluctuations; short-range order parameter; excess stability function