Thermodynamics Research Center / ThermoML | Thermochimica Acta

Thermodynamic and spectroscopic studies on the phase transition of BaHf(PO4)2

Popa, K., Konings, R. J. M., Benes, O., Geisler, T., Popa, A. F.
Thermochim. Acta 2006, 451, 1-2, 1-4
ABSTRACT
We have studied the thermal properties of BaHf(PO4)2 during the heating from the room temperature up to 1600K by thermal analysis and drop calorimetry and up to 835K by Raman spectroscopy. A phase transition appears at about 791K during heating and at 744K during cooling. For the high-temperature polymorph we determined the crystal class and the most likely space groups based on Raman spectroscopic data. The enthalpy of the transition was derived from the high-temperature heat capacity measurements.
Compounds
# Formula Name
1 BaHfO8P2 BaHf(PO4)2
Datasets
The table above is generated from the ThermoML associated json file (link above). POMD and RXND refer to PureOrMixture and Reaction Datasets. The compound numbers are included in properties, variables, and phases, if specificied; the numbers refer to the table of compounds on the left.
Type Compound-# Property Variable Constraint Phase Method #Points
  • POMD
  • 1
  • Molar enthalpy, kJ/mol ; Crystal 1
  • Lower temperature, K; Crystal 1
  • Upper temperature, K; Crystal 1
  • Pressure, kPa; Crystal 1
  • Crystal 1
  • Small sample (50 mg) DSC
  • 19
  • POMD
  • 1
  • Molar enthalpy, kJ/mol ; Crystal 2
  • Lower temperature, K; Crystal 2
  • Upper temperature, K; Crystal 2
  • Pressure, kPa; Crystal 2
  • Crystal 2
  • Small sample (50 mg) DSC
  • 9