Synthesis and High-Temperature Heat Capacity of the YbInGe2O7 and LuInGe2O7 Germanates in the Range 350—1000 K.

The YbInGe₂O₇ and LuInGe₂O₇ germanates have been prepared by solid-state reactions using stoichiometric oxide mixtures, which were sequentially fired at temperatures from 1273 to 1473 K in air, and their molar heat capacity has been determined by differential scanning calorimetry in the range 350‒1000 K. The experimental C_p(T) data obtained have been used to evaluate the enthalpy increment, entropy change, and reduced Gibbs energy of the rare-earth oxide compounds. [ABSTRACT FROM AUTHOR]