THE ENERGETICS OF CUBIC ZIRCONIA FROM SOLUTION CALORIMETRY OF YTTRIA-STABILIZED AND CALCIA-STABILIZED ZIRCONIA

High-temperature solution calorimetry of monoclinic zirconia, yttria- and calcia-stabilized zirconia cubic solution (m-ZrO2, YSZ and CSZ, re spectively) was performed in lead berate (2 PbO . B2O3) at 975 K and 1 045 K. Two independent data sets of enthalpy of solution of stabilized zirconia show that the enthalpy of the monoclinic-to-cubic phase tran sition of zirconia is Delta H (m --> c) = +13.5+/-2.2 kJ/mol. This is in agreement with an estimated value of + 12.24 kJ/mol for this transi tion [1].