Heat Capacity of In2Ge2O7 and YInGe2O7 from 320 to 1000 K

Polycrystalline In2Ge2O7 and YInGe2O7 samples have been prepared by solid-state reactions, by sequentially firing stoichiometric mixtures of In2O3, Y2O3, and GeO2 at temperatures from 1273 to 1473 K. The molar heat capacity of the indium and yttrium indium pyrogermanates has been determined by differential scanning calorimetry in the range 320-1000 K. The experimental C-p(T) data have been used to evaluate the enthalpy increment, entropy change, and reduced Gibbs energy of In2Ge2O7 and YInGe2O7.