Effects of Fabrication Conditions on the Crystallinity, Barium Deficiency, and Conductivity of BaZr0.8Y0.2O3-delta Films Grown by Pulsed Laser Deposition

Abstract

Yttrium-doped barium zirconate (BZY) thin films were deposited on MgO and sapphire substrates using a pulsed-laser deposition (PLD) method with varying deposition rates. The films deposited with a low deposition rate exhibited highly oriented microstructures with little grain boundaries. The electrical conductivities of these films were higher than those of the films, deposited with high deposition rates, which showed little-oriented polycrystalline microstructure. While the films deposited on the MgO substrates had a stoichiometric composition, those deposited on the sapphire substrates had a high barium deficiency, which was possibly due to the differences in the crystal structure and large lattice mismatch between the sapphire substrate and the BZY film. The electrical conductivity of the highly oriented BZY film, grown on MgO substrate with a low deposition rate, showed little barium deficiency and the highest conductivity value that is higher than the typical conductivity of sintered pellets.