Piezo-ferroelectrics: Pressure-induced phase transitions in Pb(Zr1-xTix)O3 (PZT)

TL;DR

This study investigates pressure-induced phase transitions in PZT piezoelectric materials, revealing a sequence of structural changes linked to enhanced piezoelectric properties, with implications for future material optimization.

Contribution

It identifies a specific pressure-driven phase transition sequence in PZT, connecting structural changes to piezoelectric performance, which was not previously characterized in detail.

Findings

Pressure induces phase transitions to monoclinic phases in PZT.

Transformation sequence identified: P4mm -> Cm -> Cc -> F1 -> F-1.

Compression involves polarization rotation and octahedral tilting.

Abstract

Piezoelectric PZT solid solutions were studied as a function of pressure and temperature. Moderate pressure is found to induce phase transitions to monoclinic phases (Cm,Cc) for Ti-rich PZT, which are the same ferroelectric phases responsible for the high piezoelectric properties of the MPB. The following transformation sequence P4mm -> Cm -> Cc -> F1 -> F-1 was identified upon increasing pressure. Compression behaviour is dominated by: (1) a rotation and a reduction of the spontaneouspolarization and (2) octahedral tilting leading to unit cell doubling. Future studies as a function of pressure, temperature and electric field on single crystals of heterovalent relaxor ferroelectric isotypes of PZT are proposed in order to better understand these potentially technologically-important piezoferroelectric materials.