Study On Preparation And Dielectric Property Of BaTiO₃/PVDF Composite Films

Ceramic/polymer composites, which combines processibility and flexility ofpolymer, is a promising material in electrical engineering and electronic industryfields, such as dielectric in capacitors with all kinds of shape. The trend ofminiaturization and multi-functionality of electron components requires thatdielectric materials have dielectric constant as high as possible. Therefore, it isvery significant for improving the dielectric constant of the ceramic/polymercomposites.This paper consider BaTiO₃ as a filler to study its preparation, microstructure,dielectric properties, and also PVDF as a base to discuss BaTiO₃/PVDF compositefilm dielectric properties. Respectively sol-gel method and copreeipitation methodto prepare barium titanate powder also synthesized powders were characterized byDSC, FT-IR, XRD, SEM)and do ceramic experiment and test their performance.The results showed that sol-gel method of the particle size is smaller, moreuniform distribution, the co-precipitation method is simple, nontoxic, and higheryields. Two methods can make the reunion occurred powder, which issoftreunionand could be removed. Sol-gel and precipitation can be produced in thenanometer size of the cubic perovskite structure BaTiO₃ powder and the ceramicwhich is made by three kinds of rare earth (La, Ce, Dy) modified powder foundthat the dielectric properties of Ce-doped BaTiO₃ has the most obviousimprovement in the department reached a maximum of 0.4% around 1250; WhenLa₂O₃ doping amount of 0.6%, the dielectric constant change to be the largest 460and dielectric loss is 0.045. Dy₂O₃ doping amount of 1.2% when 650 is the largestdielectric constant, dielectric loss at this time is very small,just only 0.03.Three modified BaTiO₃/PVDF composite film dielectric properties than purePVDF film's.And Dy which modified the BaTiO₃/PVDF film most excellent performance (ε≈143), followed by the film La modified (ε≈130), and finally theCe (ε≈112). Composite Materials dielectric constant and dielectric loss increaseas BaTiO₃ content increases.In general speaking, the results in the work have a great help for theapplication of the novel high-dielectric-constant BaTiO₃/PVDF composites.