Journal of Chemical Thermodynamics, Vol.43, No.6, 970-973, 2011
Heat capacity of hafnia at low temperature
The low temperature (2 to 300) K heat capacity of monoclinic hafnia (HfO2) was measured using the heat capacity option of a Quantum Design Physical Property Measurement System (PPMS). The thermodynamic functions in this temperature range were derived by curve fitting. The standard entropy and enthalpy of hafnia at T = 298.15 K was calculated to be 56.15 +/- 0.57 J.mol(-1).K-1 and 9.34 +/- 0.09 kJ.mol(-1), respectively. The results are in fairly good agreement with old data, which only covered temperatures from (50 to 298) K. Hafnia has a higher heat capacity than zirconia at all temperatures from (2 to 300) K. Published by Elsevier Ltd.