Dielectrical, optical, and structural characterization of TiO₂/PVA nanocomposite films for dielectric applications

In this study, titanium dioxide/poly(vinyl) alcohol (TiO₂/PVA) nanocomposite thin films were prepared by a simple spin-coating method for dielectric applications. Structural, morphological, optical, and dielectric properties of samples were analyzed by XRD, SEM, AFM, UV-VIS, and dielectric measurements. The effect of TiO₂ nanoparticles on these properties was investigated. It was found that TiO₂ nanoparticles lead to increase the crystallinity of nanocomposites. As TiO₂ content in the composite structure increases, while average transmittance values decrease, reflectance values increase. The dielectric parameters such as real and imaginary part of complex permittivity which are related to the stored energy and the dissipation (or loss) of energy were significantly affected by the presence of TiO₂ nanoparticles. In addition, alternating current (A.C.) conductivity increased with increasing applied frequency. The A.C. conductivity also confirmed that all the samples exhibited the insulator behavior and obeyed the universal power law.