Characterization of Strontium Modified Lanthanide Cobaltites and Ferrites as Perovskite Electrodes in Potentiometric Oxygen Sensors

摘要

A comparative study on applicability of Sr doped perovskites with formula A_(1-x)Sr_xBO_(3-δ)(A = La, Nd, Sm; B = Fe or Co) in potentiometric oxygen sensors was conducted. Oxygen concentration cells were fabricated employing yttria stabilized zirconia (YSZ) discs as substrates. Perovskite powders obtained through solid state reaction method were used for paste preparation, subsequently screen printed onto YSZ substrate as top and bottom electrodes. Electromotive force of the fabricated cells was measured as a function of temperature. In order to better elucidate the obtained results, resistivity of each perovskite electrode was measured for a wide temperature range and the influence of firing temperature of the electrodes was investigated. Furthermore, response times were measured and suitable candidates for application in potentiometric oxygen sensors were indicated.