Correlation between excess volume and thermodynamic functions of liquid Pd-X (X = Fe, Cu and Ni) binary systems

Binary systems Pd-X (X = Fe and Cu) have order-disorder transformations in solid-solution ranges. A sensitive parameter to atomic arrangement for a solution is the excess volume, which in itself is interesting from a thermodynamic perspective. In this study, using a combination of electromagnetic levitation and a static magnetic field, accurate measurements were taken of the density of liquid Pd-X alloys from which excess volumes were evaluated. The excess volumes of these binary systems were positive over the entire composition range. Hence, these order-disorder transformation systems have positive excess volumes in their liquid states. The results are analyzed using thermodynamic functions such as the excess Gibbs energy and enthalpy of mixing.