ABSTRACT

Alkaline earth chloroapatites, M10(PO4)6Cl2 (M=Ba, Sr, Ca) were prepared by solid state reaction route and characterized by XRD. The lattice constants of Ba10(PO4)6Cl2, Sr10(PO4)6Cl2, Ca10(PO4)6Cl2 were determined to be a=10.27(1)A, c=7.66(1)A ; a=9.87(2)A, c=7.18(1)A and a=9.52(1)A, c=6.85(1)A respectively. The enthalpy increments were measured by inverse drop calorimetric method in the temperature range 523-1423 K using a high temperature calorimeter. Thermodynamic functions such as heat capacity, entropy and Gibbs energy functions in the temperature range 298-1500 K, were computed from the measured enthalpy increments.

Compounds

#	Formula	Name
1	Ca10Cl2O24P6	calcium chloride phosphate Ca10(PO4)6Cl2
2	Cl2O24P6Sr10	strontium chloride phosphate Sr10(PO4)6Cl2
3	Ba10Cl2O24P6	barium chloroapatite

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 enthalpy, kJ/mol ; Crystal	Temperature, K; Crystal	Pressure, kPa; Crystal	Crystal	Drop calorimetry	19
POMD	1	Molar heat capacity at constant pressure, J/K/mol ; Crystal	Temperature, K; Crystal	Pressure, kPa; Crystal	Crystal	Drop calorimetry	14
POMD	2	Mass density, kg/m3 ; Crystal	Temperature, K; Crystal Pressure, kPa; Crystal		Crystal	X-ray diffraction	1
POMD	2	Molar enthalpy, kJ/mol ; Crystal	Temperature, K; Crystal	Pressure, kPa; Crystal	Crystal	Drop calorimetry	19
POMD	2	Molar heat capacity at constant pressure, J/K/mol ; Crystal	Temperature, K; Crystal	Pressure, kPa; Crystal	Crystal	Drop calorimetry	14
POMD	3	Mass density, kg/m3 ; Crystal	Temperature, K; Crystal Pressure, kPa; Crystal		Crystal	X-ray diffraction	1
POMD	3	Molar enthalpy, kJ/mol ; Crystal	Temperature, K; Crystal	Pressure, kPa; Crystal	Crystal	Drop calorimetry	19
POMD	3	Molar heat capacity at constant pressure, J/K/mol ; Crystal	Temperature, K; Crystal	Pressure, kPa; Crystal	Crystal	Drop calorimetry	14

Thermodynamics Research Center / ThermoML | Thermochimica Acta

Thermodynamic functions of alkaline earth chloroapatites M10(PO4)6Cl2 (M=Ba, Sr, Ca) by drop calorimetry

Babu, R., Jena, H.[Hrudananda], Govindan Kutty, K. V., Nagarajan, K.

ABSTRACT