Structural and Electrical Characterisation of Barium Zirconate Protonic Conductor Co-Sputter Deposited Coatings

摘要

BaZr_(1-x)Y_xO_(3-α) coatings were co-sputtered from metallic Zr-Y (84-16 at.%) and Ba targets in the presence of a reactive argon-oxygen gas mixture. The structural and chemical features of the film were assessed by X-ray diffraction and Scanning Electron Microscopy, respectively. The as-deposited coatings are amorphous and crystallise after annealing at around 423 K in the convenient perovskite structure (cubic, Pm-3m). It was shown that BaZrO3 coatings are stable towards hydration and carbonation after annealing treatments in air at different temperatures, up to 973 K. The SEM observation revealed that as-deposited coatings are dense, but some cracks appear during the crystallisation treatment. To avoid the coatings cracking during the crystallisation process, they were also deposited in situ at temperatures around 523 K. In this case, the as-deposited coatings are crystallized under cubic structure of BaZrO3 and cracks are observed neither before nor after annealing at 973 K during 2 hours.^