Alternative model of a 1-1-3 composite, its piezoelectric properties and figures of merit

Abstract

A model of a novel 1-3-type composite containing two ferroelectric components is put forward. In this composite, ferroelectric single crystal (SC) rods and ferroelectric ceramic rods are distributed in a polymer matrix. For a lead-free 1-1-3 composite based on domain-engineered [Lix(K1-yNay)1-x](Nb1-zTaz)O3:Mn SC, effective piezoelectric coefficients d3j∗ - and g3j∗ - and energy-harvesting figures of merit (FOMs) d3j∗ - g3j∗ - are studied taking an active influence of the ferroelectric components into account. In a new m-mc diagram, regions of volume fractions of SC (m) and ceramic (mc) are determined where FOM d33∗ - g33∗ - changes from 6 · 10-11 to 9 · 10-11 Pa-1. Effective parameters of the 1-1-3 and related 1-0-3 composites are compared, and consistency is shown. The large longitudinal piezoelectric coefficient g33∗ - and FOM d33∗ - g33∗ - of the lead-free 1-1-3 composite are to be of interest in piezoelectric sensorics and energy harvesting.