Structure, microstructure and dielectric studies of PVA/Sr(Co_1/3Nb_2/3)O₃ polymer composites

Polymer-Ceramic composite films of Polyvinyl alcohol (PVA) and Sr(Co_1/3Nb_2/3)O₃ (SCN) as filler, were prepared by solution casting technique. The structure and microstructure of the samples has been characterized using X-ray diffraction, infrared spectroscopy (Fourier transformed infrared spectroscopy) and Scanning electron microscopy (SEM). Thermal properties of the samples are studied by means of Differential Scanning Calorimetry (DSC) revealed that the glass transition temperature increases for the composites [PVA + 10% SCN (T_g = 109°C)] compared to pure PVA (T_g = 97°C) samples. The dielectric characterization has been studied by means of impedance gain-phase analyzer. It is concluded that addition of 50% SCN lead to significant advantage on the dielectric properties of Polyvinyl alcohol polymers. Observed changes in the dielectric dispersion at high temperatures are essentially linked to the glass transition temperature (T_g) rather than due to lattice based dielectric dispersion.