On the thermodynamic aspect of zinc oxide polymorphism. Calorimetric study of metastable rock salt ZnO

The enthalpies of dissolution of metastable rock salt and thermodynamically stable wurtzite polymorphs of zinc oxide in aqueous H2SO4 have been measured in direct calorimetric experiments at 303 K and 0.1 MPa and the obtained results enabled determination of the standard enthalpy of the rock salt-to-wurtzite phase transition in ZnO, {\Delta}trH = -11.7+/-0.3 kJ/mol.