Energetic characteristics of barium cerates doped by yttrium, gadolinium and luthetium oxides

Highlights: • We measured standard enthalpies of formation BaCe_0.8Y_0.1R_0.1O_2.9 (R = Gd, Lu). • We calculated stabilization energies for BaCe_0.8Y_0.1R_0.1O_2.9. • We calculated lattice energies for BaCe_0.8Y_0.1R_0.1O_2.9. For the first time solution enthalpies of BaCe_0.8Y_0.1Gd_0.1O_2.9, BaCe_0.8Y_0.1Lu_0.1O_2.9 and mixtures of BaCl₂ + 0.8CeCl₃ + 0.1YCl₃ + 0.1GdCl₃, BaCl₂ + 0.8CeCl₃ + 0.1YCl₃ + 0.1LuCl₃ in 1 mol dm⁻³ HCl with 0.1 mol dm⁻³ KI have been measured. On the basis of experimental data obtained and literature data the standard molar enthalpies of formation and stabilization energies were calculated. Using Born-Haber cycle the lattice energies were calculated. It was established that lattice energy was increased from BaCe_0.8Y_0.1Gd_0.1O_2.9 to BaCe_0.8Y_0.1Lu_0.1O_2.9. It correlates with decreasing of ion radius of rare earth element from gadolinium to lutetium. Increasing of lattice energy with decreasing of ion radius of rare earth element was explained with modified formula of Kapustinskii.