Understanding the effect of porosity on the polarisation-field response of ferroelectric materials

TL;DR

This study combines experiments and modeling to analyze how porosity affects the electric field response and hysteresis behavior of ferroelectric materials, clarifying conflicting observations in existing literature.

Contribution

It introduces a new approach to understanding the impact of porosity level and morphology on ferroelectric polarization and hysteresis, aiding material design.

Findings

Porosity broadens electric field distribution and reduces local field strength.

Coercive field variation with porosity is governed by competing mechanisms.

Insights support improved design of ferroelectric devices for sensors and energy applications.

Abstract

This paper combines experimental and modelling studies to provide a detailed examination of the influence of porosity volume fraction and morphology on the polarisation-electric field response of ferroelectric materials. The broadening of the electric field distribution and a decrease in the electric field experienced by the ferroelectric ceramic medium due to the presence of low-permittivity pores is examined and its implications on the shape of the hysteresis loop, remnant polarisation and coercive field is discussed. The variation of coercive field with porosity level is seen to be complex and is attributed to two competing mechanisms where at high porosity levels the influence of the broadening of the electric field distribution dominates, while at low porosity levels an increase in the compliance of the matrix is more important. This new approach to understanding these materials enables the seemingly conflicting observations in the existing literature to be clarified and provides an effective approach to interpret the influence of pore fraction and morphology on the polarisation behaviour of ferroelectrics. Such information provides new insights in the interpretation of the physical properties of porous ferroelectric materials to inform future effort in the design of ferroelectric materials for piezoelectric sensor, actuator, energy harvesting, and transducer applications.