Synthesis and Thermodynamic Properties of Germanate Tb2Ge2O7

Abstract

Germanate Tb₂Ge₂O₇ has been prepared by solid-phase synthesis from a stoichiometric mixture of Tb₂O₃ and GeO₂ by sequential firing in air at temperatures of 1273–1473 K. The effect of temperature on its molar heat capacity has been studied by differential scanning calorimetry. According to the obtained dependence C_p = f(T), the thermodynamic properties (enthalpy and entropy changes and the reduced Gibbs energy) have been calculated, and the specific heat value at 298 K has been estimated.