TY - JOUR
T1 - Experimental studies and thermodynamic assessment of the Ba-Mo-O system by the CALPHAD method
AU - Smith, A. L.
AU - Rutten, M.
AU - Herrmann, L.
AU - Epifano, E.
AU - Konings, R. J.M.
AU - Colineau, E.
AU - Griveau, J. C.
AU - Guéneau, C.
AU - Dupin, N.
PY - 2021
Y1 - 2021
N2 - Thermodynamic measurements on BaMoO4, BaMoO3 and BaMo3O10 are reported, that served as input for the development of a thermodynamic model of the Ba-Mo-O system using the CALPHAD methodology. The valence states of molybdenum in BaMoO4 and BaMoO3 were confirmed to be VI and IV, respectively, from X-ray Absorption Near Edge Structure Spectroscopy measurements at the Mo K-edge. The heat capacity at low temperatures of these compounds was obtained from thermal-relaxation calorimetry. Phase equilibrium data in the BaMoO4-MoO3 section were also measured, and the transition enthalpy associated with the peritectic decomposition of BaMo3O10 was determined using Differential Scanning Calorimetry. The developed thermodynamic model used the compound energy formalism for intermediate compounds, and an ionic two-sublattice model for the liquid phase. The optimized Gibbs energies were assessed with respect to the known thermodynamic and phase equilibrium data. A good agreement is generally obtained, but a number of ill-defined data were also identified.
AB - Thermodynamic measurements on BaMoO4, BaMoO3 and BaMo3O10 are reported, that served as input for the development of a thermodynamic model of the Ba-Mo-O system using the CALPHAD methodology. The valence states of molybdenum in BaMoO4 and BaMoO3 were confirmed to be VI and IV, respectively, from X-ray Absorption Near Edge Structure Spectroscopy measurements at the Mo K-edge. The heat capacity at low temperatures of these compounds was obtained from thermal-relaxation calorimetry. Phase equilibrium data in the BaMoO4-MoO3 section were also measured, and the transition enthalpy associated with the peritectic decomposition of BaMo3O10 was determined using Differential Scanning Calorimetry. The developed thermodynamic model used the compound energy formalism for intermediate compounds, and an ionic two-sublattice model for the liquid phase. The optimized Gibbs energies were assessed with respect to the known thermodynamic and phase equilibrium data. A good agreement is generally obtained, but a number of ill-defined data were also identified.
KW - Barium-molybdenum-oxygen system
KW - CALPHAD
KW - Differential Scanning Calorimetry
KW - Thermal-relaxation calorimetry
KW - XANES
UR - http://www.scopus.com/inward/record.url?scp=85100116063&partnerID=8YFLogxK
U2 - 10.1016/j.jeurceramsoc.2021.01.010
DO - 10.1016/j.jeurceramsoc.2021.01.010
M3 - Article
AN - SCOPUS:85100116063
SN - 0955-2219
VL - 41
SP - 3664
EP - 3686
JO - Journal of the European Ceramic Society
JF - Journal of the European Ceramic Society
IS - 6
ER -