Heat Capacity and Thermodynamic Properties of La3TaO7

Abstract

The molar heat capacity of lanthanum tantalate La₃TaO₇ of the weberite structural type was measured by the relaxation, adiabatic, and differential scanning calorimetry methods in the temperature range of 0–1860 K; the thermodynamic properties: entropy and enthalpy increment were calculated from the smoothed values of heat capacity; the Gibbs energy of formation of lanthanum tantalate from binary oxides in the high-temperature region was estimated; and La₃TaO₇ was shown to have high stability.