A high temperature study on the structure, linear expansion, thermodynamic stability and electrical properties of the BaCe0.8Pr0.2O3-δ perovskite

BASBUS J.F.; ARCE M.D.; PRADO F.P.; SUESCUN L.; CANEIRO A.; MOGNI L.V

JOURNAL OF THE ELECTROCHEMICAL SOCIETY

ELECTROCHEMICAL SOC INC

Año: 2016 vol. 163 p. 516 - 522

0013-4651

Single phase BaCe0.8Pr0.2O3−δ perovkite was obtained by the modified Pechini method followed by self-combustion and sintering at 1350◦C. Crystal structure, thermodynamic stability, linear expansion and electrical properties were characterized as a function of temperature, under oxidizing and reducing atmospheres. BaCe0.8Pr0.2O3−δ presents phase transitions under both atmospheres, which do not compromise the transport properties. The electrical conductivity showed a mixed character, dominated by electronic and oxygen vacancies transport in O2-containing atmosphere. Pr+4 reduction was observed above 400◦C under H2-containing atmosphere. This reduction increases the oxygen non-stoichiometry and OH? charge carriers concentration, unit cell volume andthermal expansion coefficients (TECs). Pr+4 reduction suppresses the electronic conduction and hence the transport number for OH? would be dominant in wet reducing atmosphere.