Abstract: | The heat capacities of Pb2V2O7 and Pb3(VO4)2 as a function of temperature in the range 350–965 K have been studied by the differential scanning calorimetry method. The CP = f(T) curve for Pb2V2O7 is described by the equation Cp = (230.76 ± 0.51) + (73.60 ± 0.50)×10-3T ? (18.38 ± 0.54)×105T-2 in the entire temperature range. For Pb3(VO4)2, there is a well-pronounced extreme point in the CP = f(T) curve at T = 371.5 K, which is caused by the existence of a structural phase transition. The thermodynamic properties of the oxide compounds have been calculated. |