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

Abstract

Gibbs 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) = 21.21 kPa)/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: {D_f G^O (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 298.15 K.