Characterization of dielectric and electro-optic properties of PLZT 9/65/35 films on sapphire for electro-optic applications

Lead lanthanum zirconate titanate (PLZT) thin films were deposited on r-plane sapphire at low temperatures by RF triode magnetron sputtering using lead compensated hot-pressed targets. To obtain fully perovskite phase in the films, two types of post-deposition processing were investigated: rapid thermal annealing (RTA) and furnace annealing (FA). Dielectric and electro-optic properties of PLZT films were found to be strongly dependent on annealing conditions. The peak dielectric constant of the films were 1200 and 2800 with Curie temperatures of 110 degrees C and 190 degrees C after RTA and FA processing, respectively. The dielectric losses in the films were fairly low; tan deltas were less than 0.02 after RTA and less than 0.04 after FA processing. The films showed good optical transmission characteristics after annealing and an anomalously large effective quadratic electro-optic effect was observed in one furnace annealed film.