Thermodynamic properties of liquid Ga-Li alloys: Experiment vs. modeling

The integral molar enthalpy of mixing was determined by the drop calorimetric method for binary Ga-Li liquid alloys. The measurements were conducted at three temperatures, i.e. 873 K, 992 K and 1039 K, and in the following concentration ranges: XLi = 0.7030 to 0.9801, 0.0908 to 0.3748 and 0.4284 to 0.8282, respectively. A strong negative deviation from the ideal solution was observed, with the minimum value equal to −21.2 kJ/mol for XLi = 0.5421. The analysis of the experimental data suggests that the integral mixing enthalpy of the Ga-Li liquid solutions is independent of temperature. The values calculated from the Miedema's model are more positive in comparison to the measured ones, and the maximum difference of about 12.5 kJ/mol is observed for the 0.5 mol fraction of Li. By way of applying the calorimetric data from this work and the electromotive force measurements of Wen and Huggins and Yatsenko et al., the Redlich-Kister relation was worked out for the excess Gibbs energy of the liquid Ga-Li liquid solutions. The calculated Scc(0) partial structure factor points to the GaLi associates in liquids.