Thin films of apatite-type oxide ion conductors aiming at intermediate temperature SOFC

Abstract

Dense thin films of apatite-type oxide ion conductors were fabricated using DC plasma spraying. Apatite and amorphous phases were observed in XRD patterns of the as-deposited films which exhibited no ionic conduction. On heating at 1073 K, the films showed bulk ionic conduction with grain boundary and electrode interface components in the AC impedance measurements. The bulk ionic conductivity measured at 1073 K increased up to 2 mS cm^-1 when heated above 1173 K.