Thermodynamic properties of the pyrochlore Gd₂Ru₂O₇(s) by solid oxide electrochemical cell

945-948Gibbs energy of formation of Gd2Ru2O7(s) has been determined using solid state electrochemical technique employing oxide ion conducting electrolyte. The reversible electromotive force of the following solid-state electrochemical cell, (-)Pt/{Gd2O3(s) + Gd2Ru2O7(s) + Ru(s)}//CSZ//O2(p(O2) = 21.21kPa)/Pt(+) has been measured. The Gibbs energy of formation of Gd2Ru2O7(s) from elements in their standard state, calculated by the least squares regression analysis of the data obtained in the present study, is represented by: {f GO (Gd2Ru2O7, s)/(kJ mol-1) ±1.7} = –2549.1+0.6438· (T/K);1030.9 ≤ T/K ≤ 1193.6. The second law method gives the value of standard molar enthalpy of formation of the compound from the elements at 298.15K