Deposition And Properties Of [(Pb,La)(Zr,Ti)O₃] Ferroelectric Thin Films On ITO-Coated Glass Substrate

In recent years, PLZT ferroelectric thin films have gained attention in processing methods and applications. Early work on the fabrication of ceramic thin films was mainly based on vacuum deposition techniques such as ion beam deposition and sputtering. But vacuum techniques have restricted the deposition of device-quality films due to problems of poor stoichiometric control and complex sets of deposition parameters.The sol-gel process, has gained more attention, in comparison to other techniques, due to its inherent advantages, such as greater stoichiometric control, film homogeneity, lower processing temperatures, and lower cost. In the present work ,PLZT ferroelectric thin films with perovskite structure were prepared on Sn-doped In2O3 ( ITO) substrates with various doping by a sol-gel process. The microstrcture,electric properties, ferroelectric hysteresis loops and leakage current density of the prepared thin films after Rapid Thermal Annealing (RTA) were investigated. The results show that PLZT can be crystallized well on ITO substrate and the main texture is (101),the PLZT films annealed at 650oC have good ferroelectric properties, electric properties and I-V properties. The Pr values of the films is 36.5μC/cm2, and the EC values of the films is 45.2KV/cm. The ferroelectric properties of the deposited thin films were measured. At an applied electric field of 15V , the remnant polarization Pr and coercive field Ec of the 5mol% La-doped PLZT thin film sintered at 650 ℃were obtained from the P-V loop measurements about 35.4μC/cm2 and 111 kV/cm , respectively .At a frequency of 1 kHz, the dielectric constant and loss factor of the PLZT thin film were 984 and 0.07, respectively. The leakage current density of the PLZT film was no more than 10-8A/cm2 at the applied voltage of 9 V.