Determination and modeling of the thermodynamic properties of liquid calcium-antimony alloys

作者：Poizeau Sophie; Kim Hojong; Newhouse Jocelyn M; Spatocco Brian L; Sadoway Donald R^*

来源：Electrochimica Acta, 2012, 76: 8-15.

DOI：10.1016/j.electacta.2012.04.139

• Ca-Sb
• Liquid alloy
• Thermodynamic properties
• Association model
• Molecular interaction volume model

The thermodynamic properties of Ca-Sb alloys were determined by emf measurements in a cell configured as Ca(s)vertical bar CaF2 vertical bar Ca-Sb over the temperature range 550-830 degrees C. Activity coefficients of Ca and Sb, enthalpy, Gibbs free energy, and entropy of mixing of Ca-Sb alloys were calculated for xc(a) < 0.55. To explain the connection between short-range order of liquid Ca-Sb alloys and the strong deviation from ideality in the thermodynamic properties, two thermodynamic models were invoked and reconciled: the regular associated solution model, assuming the presence of a CaSb2 associate, and the molecular interaction volume model (MIVM). For the first time, the MIVM was used successfully to model the activity coefficients of a system with high-melting intermetallics, reducing the number of fitting parameters necessary from 5 (regular associated model) to 2 (MIVM). From the interaction parameters optimized by fitting at 800 degrees C, the with an average error of less than value.

• 出版日期2012-8-1