Synthesis, hydration, and electric properties of chlorine-substituted brownmillerite Ba1.95In2O4.9Cl0.1

Chlorine-substituted brownmillerite Ba 1.95 In 2 O 4.9 C l0.1 was obtained from barium indate Ba 2 In 2 O 5 by solid-phase synthesis. The ability to absorb water from the gas phase was confirmed by thermogravimetric studies. The transport properties were studied while varying the thermodynamic parameters of the external environment ( T , p O 2 , p H 2 O). The chloride ions in the oxygen sublattice of barium indate Ba 2 In 2 O 5 were found to affect the ion conductivity. In a humid atmosphere, the sample exhibited proton conductivity ( E a = 0.54 eV), whose contribution became dominant below 300°C.