High-temperature heat capacity and vibrational spectra of Eu2Sn2O7

摘要

The Eu2Sn2O7 compound has been prepared by solid-state reaction (by sequentially firing a stoichiometric mixture of Eu2O3 and SnO2 in air at 1273 and 1473 K) and its heat capacity has been determined by differential scanning calorimetry in the temperature range 370-1000 K. The heat capacity data have been used to evaluate the thermodynamic properties of europium stannate: enthalpy increment HA degrees(T)-HA degrees(370 K), entropy change SA degrees(T)-SA degrees(370 K), and reduced Gibbs energy Dcurrency signA degrees(T). Raman spectra of Eu2Sn2O7 polycrystals with the pyrochlore structure have been measured in the range 200-1200 cm(-1).