Polymer matrix ferroelectric composites under pressure: Negative electric capacitance and glassy dynamics

Eur Phys J E Soft Matter. 2019 Sep 9;42(9):118. doi: 10.1140/epje/i2019-11876-9.

Abstract

This report presents the results of high-pressure and broadband dielectric spectroscopy studies in polyvinylidene difluoride (PVDF) and barium strontium titanate (BST) microparticles composites (BST/PVDF). It shows that the Arrhenius behaviour for the temperature-related dynamics under atmospheric pressure is coupled to Super-Arrhenius/Super-Barus isothermal pressure changes of the primary relaxation time. Following these results, an explanation of the unique behaviour of the BST/PVDF composite is proposed. Subsequently, it is shown that when approaching the GPa domain the negative electric capacitance phenomenon occurs.

Keywords: Soft Matter: Polymers and Polyelectrolytes.