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

Journal Article · Wed Aug 01 00:00:00 EDT 2012 · Electrochimica Acta

DOI:https://doi.org/10.1016/j.electacta.2012.04.139· OSTI ID:1211035

Poizeau, S; Kim, H; Newhouse, JM; Spatocco, BL; Sadoway, DR

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. (C) 2012 Elsevier Ltd. All rights reserved,

• Sponsoring Organization: USDOE Advanced Research Projects Agency - Energy (ARPA-E)
• DOE Contract Number: DE-AR000047
• OSTI ID: 1211035
• Journal Information: Electrochimica Acta, Vol. 76; ISSN 0013-4686
• Country of Publication: United States
• Language: English