Investigating microstructure and dielectric properties of a composite based on Polyvinyl alcohol - CaCu3Ti4O12

The current study aims to investigate the microstructural and dielectric properties of the composite based on Polyvinyl alcohol-CaCu3Ti4O12 (CCTO-PVA) containing 0, 10, 30, and 70 wt % ceramic phase as the dielectric promoter. To this end, CCTO particles were first prepared by calcination of CuO, TiO2, and CaCO3 mixture at 1000 °C to fabricate the composite. Then, solutions with adequate amounts of PVA in water were provided, and the CCTO was added to solutions considering the composite weight percentage. Finally, the mixtures were dried at 60 °C. The X-Ray Diffraction (XRD) results of the powder indicated that upon increasing the amount of CCTO considerably, the semi-crystal peak height of the PVA would decrease. In addition, according to Scanning Electron Microscopy (SEM), the CCTO particles were dispersed preferably well in the polymeric phase. Dielectric properties were measured at 1 KHz, and the findings revealed that the dielectric constant and dissipation factors of the CCTO were measured as 1360 and 0.04, respectively. Moreover, these parameters of the PVA were obtained as 4 and 0.15, respectively. Increasing the CCTO weight percent of composites from zero to 70 % would increase the dielectric constant from 4 to 68 and reduce the dissipation factor from 0.17 to 0.04. The comparison of the dielectric constants with the results from different models indicated that the composite behavior was in good agreement with the logarithm model output.