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

Abstract For the first time solution enthalpies of BaCe 0.8 Y 0.1 Gd 0.1 O 2.9 , BaCe 0.8 Y 0.1 Lu 0.1 O 2.9 and mixtures of BaCl 2  + 0.8CeCl 3  + 0.1YCl 3  + 0.1GdCl 3 , BaCl 2  + 0.8CeCl 3  + 0.1YCl 3  + 0.1LuCl 3 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 0.8 Y 0.1 Gd 0.1 O 2.9 to BaCe 0.8 Y 0.1 Lu 0.1 O 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.