Dependence of structure and properties of Ba(Zr0.25Ti 0.75)O3 thin films on temperature and post-annealing

Abstract

Ba(Zr0.25Ti0.75)O3 thin film was deposited on a LaNiO3-coated SiO2/Si substrate by pulsed-laser deposition. Crystallinity, (h 0 0) texture and surface texture were found to be improved, and the out-of-plane lattice parameter d, polarization P, dielectric constant εr(0) and tunability nr were found to increase with increasing deposition temperature or post-annealing duration. Improvement in crystallinity is believed to be the reason for the improved properties. The increase in the out-of-plane lattice parameter of the highly (h 0 0) textured thin film causes the increases in nr and P, while the changes in εr and nr are closely associated with the changes in εr(0) and P. A high tunability of 76% measured at the frequency of 1 MHz could be achieved for the film deposited and annealed at 640 °C, showing that Ba(Zr0.25Ti0.75)O3 thin film would be a potential candidate for future tunable devices. © 2008 IOP Publishing Ltd.