Proton conductivity in Yb-doped BaZrO₃-based thin film prepared by pulsed laser deposition

For increasing the performance of PCFC (Protonic Ceramic Fuel Cells), it is important to prepare high-quality thin films of electrolyte materials. In this study, the preparation condition of the thin film of BaZr_0.8Yb_0.2O_2.9 (BZYb) by pulsed laser deposition (PLD) method was optimized and the electrical conductivities of the obtained films were measured. The thin film was prepared by PLD using two kinds of BZYb targets, which were prepared by solids state reaction and Pechini method. Both thin-film samples have the single phase of the cubic perovskite-type structure, however, morphology as well as the orientation of the BZYb film was significantly different. The thin film using the target material by Pechini method is a high crystalline orientation and partially oriented [211] direction. The electrical conductivities of the obtained thin films at reduction atmosphere are dominated by proton conductivity, which is almost the same as that of the bulk sample despite [211] orientation.