WO3 thermodynamic properties at 80–1256 K revisited

Thermodynamic properties (heat capacity Cp, entropy S°, enthalpy change ΔH° and reduced Gibbs energy ΔΦ°) of crystalline WO3 in a temperature range of 80–1256 K were refined using two complementary calorimetric methods, namely differential scanning calorimetry and adiabatic vacuum calorimetry. Enthalpy changes during a number of successive phase transitions in WO3 were calculated from differential scanning calorimetry data in both heating and cooling regimes and compared to previously reported values. For the first time, enthalpy changes for the orthorhombic to monoclinic and monoclinic to tetragonal high-temperature phase transitions in WO3 were estimated.