Synthesis and High-Temperature Heat Capacity of Sm2Ge2O7 and Eu2Ge2O7

Yb2Sn2O7 and Lu2Sn2O7 have been prepared by solid-state reactions, by firing mixtures of Yb2O3 or Lu2O3 and SnO2 at 1473 K, and the molar heat capacity of these compounds (pyrochlore structure) has been determined by differential scanning calorimetry. The C p (T) data have been used to evaluate the thermodynamic properties of the stannates: enthalpy increment, entropy change, and reduced Gibbs energy.