Thermodynamics of liquid Li-Sb alloys - Experiment vs modeling

Thermodynamic properties of liquid Li-Sb alloys have been studied both experimentally and theoretically. Electromotive force measurements (EMF) in the Li-Sb system were performed over broad range of temperature and lithium concentrations. It was found that in liquid Sb-rich alloys (xSb ≥ 0.85) the EMF increases with increasing temperature as opposite to liquid alloys of lower Sb content (0.4 ≤ xSb < 0.85). Based on the present experiment results and literature data a new thermodynamic description of the liquid Li-Sb phase was developed using associate and sub-regular models. Very good agreement between experiment and new modeling data using associate model are observed. Importance of Li3Sb intermetallic compound has been tested and proved in order to have a proper description of thermodynamic and structural properties of Li-Sb liquid alloys by comparing sub-regular with associate model data. Chemistry of short-range atom ordering has been qualified and quantified at whole Sb concentration range by using Bhatia-Thornton formalism and Warren-Cowley parameter, respectively. Significant degree of chemical ordering at Li-rich alloys has been found resulted from Li3Sb compound existence in comparison to its depletion at Sb-side where liquid Li-Sb alloys display the tendency to random atoms ordering.