Time-Resolved Nanobeam X-ray Diffraction of a Relaxor Ferroelectric Single Crystal under an Alternating Electric Field

Shinobu Aoyagi,Yasuhiko Imai,Hitoshi Osawa,Shigeru Kimura,Hiroaki Takeda,Kazushi Sumitani,Ayumi Aoyagi

doi:10.3390/cryst11111419

Abstract

Lead-containing relaxor ferroelectrics show enormous piezoelectric capabilities relating to their heterogeneous structures. Time-resolved nanobeam X-ray diffraction reveals the time and position dependences of the local lattice strain on a relaxor ferroelectric single crystal mechanically vibrating and alternately switching, as well as its polarization under an alternating electric field. The complicated time and position dependences of the Bragg intensity distributions under an alternating electric field demonstrate that nanodomains with the various lattice constants and orientations exhibiting different electric field responses exist in the measured local area, as the translation symmetry breaks to the microscale. The dynamic motion of nanodomains in the heterogeneous structure, with widely distributed local lattice strain, enables enormous piezoelectric lattice strain and fatigue-free ferroelectric polarization switching.

Highlights

Lead-containing composite perovskites, (1−x)Pb(Mg1/3 Nb2/3 )O3 −xPbTiO3 (PMNPT) and (1−x)Pb(Zn1/3 Nb2/3 )O3 −xPbTiO3 (PZN-PT), are well known as relaxor ferroelectrics and are widely used in many applications due to their excellent piezoelectric properties [1,2,3]. Their piezoelectric constants and electromechanical coupling factors strongly depend on the PbTiO3 (PT) fraction x and have a maximum value near the morphotropic phase boundary (MPB) that separates low-PT rhombohedral and high-PT
Monoclinic and orthorhombic phases exist in a narrow composition region near MPB and are induced by applying an electric field [8,10,11,14,17,18]
polar nano regions (PNRs) first occur below the Burns temperature in the high-temperature paraelectric cubic phase, expanding with cooling and coexisting with regular ferroelectric domains in low-temperature ferroelectric phases [21]

Summary

Introduction

Lead-containing composite perovskites, (1−x)Pb(Mg1/3 Nb2/3 )O3 −xPbTiO3 (PMNPT) and (1−x)Pb(Zn1/3 Nb2/3 )O3 −xPbTiO3 (PZN-PT), are well known as relaxor ferroelectrics and are widely used in many applications due to their excellent piezoelectric properties [1,2,3]. Their piezoelectric constants and electromechanical coupling factors strongly depend on the PbTiO3 (PT) fraction x and have a maximum value near the morphotropic phase boundary (MPB) that separates low-PT rhombohedral and high-PT tetragonal phases [4,5,6,7,8]. PNRs first occur below the Burns temperature in the high-temperature paraelectric cubic phase, expanding with cooling and coexisting with regular ferroelectric domains in low-temperature ferroelectric phases [21]

Methods

Results

Conclusion