Segregating to ordering transformation in In–Sn melt

Abstract

The regular associated solution model has been used to study the thermodynamic and microscopic structural properties of In-Sn liquid alloy at 700 K. We have assumed the existence of complex in the liquid mixture and estimated the mole fractions of the complexes and the unassociated monomers throughout the entire concentrations. The thermodynamic properties, such as the free energy of mixing (), the enthalpy of mixing (), the entropy of mixing () and the activities of the monomers ( and ), and the microscopic structural properties, such as concentration fluctuation in long-wavelength limit () and the Warren–Cowley short-range order parameter (), have been computed using concept of the determined mole fractions. The theoretical analysis suggests that the In–Sn system behaves as homo-coordinating nature in Sn-rich region and hetero-coordinating nature in In-rich region in the liquid state. The interaction energy parameters are found to be temperature-dependent and the In–Sn liquid alloy is found to be weakly interacting system.