Structural and Electrical Properties of Solution Casted-BaTiO₃-Polyvinylidene Composite Layers

Ceramic doped-polymer structures constitute a new area of functional materials, which are very promising because they combine hardness of ceramics with plasticity, low density, and high breaking strength of polymers. Piezoelectric composites are remarkable candidates for use in technical applications such as sensors and actuators, owing to their ability to integrate electrical and mechanical signals. Here, uniform ceramic-polymer composites (0-3 type) of tetragonal BaTiO₃ powder as a ceramic filler and polyvinylidene fluoride as a polymer matrix were prepared using solution casting. X-ray diffraction analysis confirmed the existence of both ceramic and polymer crystalline phases. Field emission-scanning electron microscope was used to confirm the uniformity of the prepared composites, because for 0-3 composites it is critical to ensure a homogeneous distribution of the filler in the matrix. The layer was flexible with the total thicknesses in the 60~70 μm range. The dielectric properties of the composite layer were analyzed for frequencies ranging from 50 Hz to 1 MHz, using an LCR meter at room temperature. Dielectric permittivity measurements of the prepared ceramic-polymer composite layers revealed higher permittivity compared with a pure polyvinylidene fluoride layer.