Research On Texture And Electric Properties In PbNb_x(Zr(0.2)Ti_0.8)O₃/BiFeO₃ Multilayers Films

ABO₃ type perovskite ferroelectric has a large number of outstanding physical properties, such as piezoelectric properties, ferroelectric and pyroelectric properties, which can be used in infrared sensors, actuators drive and memory sensors and micro-electromechanical systems. Because of its very different from semiconductor in structure, the inevitable interface reaction and some fatal flaw can greatly limit their application. In recent years, People hope to improve the performance by adding the seed layer, the buffer layer or make multi-layer structures. In this paper We hope to use the higher pyroelectric properties of PbNbx(Zr0.2Ti0 .8)O₃ and a smaller dielectric constant of BiFeO₃ to synthesize a better pyroelctric materials. In this dissertation, BFO and PNZT with the different composition have been prepared by sol-gel technology. We changed the appropriate parameters to control the crystallization degree and texture type. On this basis, PNZT-BFO multilayer structures were realized by sol-gel on Pt/Si substrate, their texture content and properties were investigated by XRD ?-scan and ?-scan technology. The results show that PNZT-BFO multilayer structures entirely exhibit mixed textures of (010) and (111) in BFO, (100) and (111) in PNZT. BFO (010) texture and PNZT (111) texture are the main texture types in the films. Because the lattice are very close to the substrate with Pt(111), the 111C has a lower elastic energy when the materials are arranged parallel to the surface, which induced (111)-oriented in the films. 363-type have good ferroelectric properties and other properties, the polarization hysteresis apparently changes from single loop to double loop when the electric field reaches 175kV/cm. 363-type films have smaller dielectric constant, dielectric loss and lower leakage current density; 3% Nb doped have smaller remanent polarization and coercive field, capacitance-voltage characteristic curves show that double-ferroelectric phase coexistence when the electric field over their coercive field.2% Nb doped of 363-type films has excellent pyroelectric properties, pyroelectric coefficient and the figure of merit reach as high as 940?C/cm2K and 253?C/cm2K.