TY - JOUR
T1 - Thermodynamic properties of Ba-Pb alloys determined by EMF measurements using binary CaF2-BaF2 electrolyte
AU - Gesualdi, Jarrod
AU - Nigl, Thomas P.
AU - Lichtenstein, Timothy
AU - Smith, Nathan D.
AU - Kim, Hojong
N1 - Funding Information:
The financial support of the US Department of Energy, Office of Nuclear Energy’s Nuclear Energy University Programs (Award No. DE-NE0008425) and Integrated University Program Graduate Fellowship (Award No. DE-NE0000113) are gratefully acknowledged.
Publisher Copyright:
© The Author(s) 2019.
PY - 2019
Y1 - 2019
N2 - The thermodynamic properties of Ba-Pb alloys (activities, phase transitions, and partial molar quantities of Gibbs energy, entropy and enthalpy) were determined based on electromotive force (emf) measurements for thirteen mole fractions (xBa = 0.05–0.76) from 700–1060 K using an electrochemical cell: Ba(s) | CaF2-BaF2 | Ba(in Pb). The activity of Ba in liquid Pb was found to be as low as 2.0 × 10–10 at xBa = 0.05 and 973 K, reflecting a large excess partial molar Gibbs energy of –156 kJ mol–1 due to strong chemical interactions between Ba and Pb. Emf measurements were most reliable in the presence of a liquid phase, but were less reliable for high-melting compositions due to the formation of metastable phases during thermal cycling, confirmed by thermal and structural analyses using differential scanning calorimetry and X-ray diffraction. The experimentally-determined activity values of Ba-Pb alloys provide a new, reliable data set for further refinement in the assessment of thermodynamic properties for the Ba-Pb system.
AB - The thermodynamic properties of Ba-Pb alloys (activities, phase transitions, and partial molar quantities of Gibbs energy, entropy and enthalpy) were determined based on electromotive force (emf) measurements for thirteen mole fractions (xBa = 0.05–0.76) from 700–1060 K using an electrochemical cell: Ba(s) | CaF2-BaF2 | Ba(in Pb). The activity of Ba in liquid Pb was found to be as low as 2.0 × 10–10 at xBa = 0.05 and 973 K, reflecting a large excess partial molar Gibbs energy of –156 kJ mol–1 due to strong chemical interactions between Ba and Pb. Emf measurements were most reliable in the presence of a liquid phase, but were less reliable for high-melting compositions due to the formation of metastable phases during thermal cycling, confirmed by thermal and structural analyses using differential scanning calorimetry and X-ray diffraction. The experimentally-determined activity values of Ba-Pb alloys provide a new, reliable data set for further refinement in the assessment of thermodynamic properties for the Ba-Pb system.
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U2 - 10.1149/2.0191908jes
DO - 10.1149/2.0191908jes
M3 - Article
AN - SCOPUS:85073198934
SN - 0013-4651
VL - 166
SP - D268-D275
JO - Journal of the Electrochemical Society
JF - Journal of the Electrochemical Society
IS - 8
ER -