Thermodynamic Properties of Li-Sb Liquid Solution by QAM

Abstract

The optimization of the thermodynamic properties of a liquid Li-Sb system is performed based on all available literature data. The description of the excess Gibbs energy as a function of temperature and composition is presented using a qualitative associate model (QAM), described in our earlier work on the Li-Pb system. The modeled molar mixing enthalpy changes, excess Gibbs energy and the molar excess entropy values are characterized by strong negative deviations from the ideal solution in the entire concentration range. It was found that the best correlation between experimental data and those calculated using QAM is observed if the Li3Sb and LiSb associates are assumed to be in the liquid Li-Sb solution. Calculations of the microscopic function, i.e., the concentration-concentration in the long-wavelength limit, (Scc(0)) excess stability function (ES) and short-range-order parameter (SRO(α)) show the extreme (maximum or minimum) values almost exactly for the concentrations of Li3Sb associate (and intermetallic phase in solid alloys) and LiSb. The quotient of real Scc(0) to this for the ideal solution (Scc(0)id) is characterized by a similar property to the mentioned structure factors.