Influence of (0.19HfO2-0.81ZrO2) ceramics filler content on structural and dielectric properties of PVDF polymer

The rapid evolution of modern technology for the sustainable development of human beings demands eco-friendly, flexible, cost-effective, and lightweight smart materials. Ceramics-polymer composites are those novel materials with improved features, which fulfill the prerequisite conditions for application in flexible devices. Pristine PVDF is one of such electroactive flexible polymers which exhibits good dielectric, ferroelectric and piezoelectric properties. But, its functional properties in the perspective of device application still need improvement and this can be achieved by adding filler to the pure PVDF. In this communication, we have reported the influence of Hafnia-Zirconia (HZ) ceramics (0.19HfO2-0.81ZrO2) filler on structural, microstructural, dielectric, and electrical properties of pure PVDF matrix. The polymer-ceramics flexible composites are synthesized by an eco-friendly and cost-effective method i.e., solution casting method. The phase formation of flexible composites is confirmed from the room temperature XRD spectra. The degree of crystallinity increases with an increase in filler content. The degree of β-phase crystallinity is found to be maximum for 5 wt% of the ceramics filler. An enhanced dielectric constant of ~53 and 20 was observed (as expected) for 5 and 10 wt% of HZ ceramics filler respectively at 100 Hz due to the enrichment of polar β-phase for these two ceramics-polymer composites. The influence of filler content on the dielectric properties was explained based on the percolation model. Relaxation and conduction mechanisms of flexible composites are analyzed from the impedance spectroscopy and ac conductivity study, respectively.