Thermodynamics Research Center / ThermoML | Thermochimica Acta

Heat capacity of Sr10(PO4)6Cl2 and Ca10(PO4)6Cl2 by DSC

Krishnan, R. V., Jena, H.[Hrudananda], Kutty, K. V. G., Nagarajan, K.
Thermochim. Acta 2008, 478, 1-2, 13-16
ABSTRACT
Strontium and calcium chloroapatites were synthesized by wet chemical method, characterized by X-ray diffraction and are found to be phase pure materials. The measured room temperature lattice parameter of Ca10(PO4)6Cl2 is a = 9.523 A, c = 6.855A and for Sr10(PO4)6Cl2 is a = 9.876A, c = 7.188 A. Heat capacity measurements were carried out on Ca10(PO4)6Cl2 and Sr10(PO4)6Cl2 by DSC in the temperature range 298 800K. The heat capacity values of Sr10(PO4)6Cl2 is higher at all temperatures than Ca10(PO4)6Cl2. Enthalpy and entropy incrementswere computed. Heat capacity values of Ca10(PO4)6Cl2 and Sr10(PO4)6Cl2 at 298K are 758 and 868 JK-1 mol-1, respectively.
Compounds
# Formula Name
1 Cl2O24P6Sr10 strontium chloride phosphate Sr10(PO4)6Cl2
2 Ca10Cl2O24P6 calcium chloride phosphate Ca10(PO4)6Cl2
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
  • Mass density, kg/m3 ; Crystal
  • Temperature, K; Crystal
  • Pressure, kPa; Crystal
  • Crystal
  • X-ray diffraction
  • 1
  • POMD
  • 1
  • Molar heat capacity at constant pressure, J/K/mol ; Crystal
  • Temperature, K; Crystal
  • Pressure, kPa; Crystal
  • Crystal
  • Small sample (50 mg) DSC
  • 27
  • POMD
  • 2
  • Mass density, kg/m3 ; Crystal
  • Temperature, K; Crystal
  • Pressure, kPa; Crystal
  • Crystal
  • X-ray diffraction
  • 1
  • POMD
  • 2
  • Molar heat capacity at constant pressure, J/K/mol ; Crystal
  • Temperature, K; Crystal
  • Pressure, kPa; Crystal
  • Crystal
  • Small sample (50 mg) DSC
  • 27