Characteristic ferroelectric domains and their dynamic behavior in ordered Pb(Sc$_{1/2}$Nb$_{1/2}$)O$_{3}$

TL;DR

This study reveals the complex ferroelectric domain structures and their dynamic behavior in chemically ordered Pb(Sc$_{1/2}$Nb$_{1/2}$)O$_{3}$, highlighting the influence of chemical order on ferroelectric microstructures and phase transitions.

Contribution

It uncovers meandering ferroelectric domains and their dynamic behavior in ordered Pb(Sc$_{1/2}$Nb$_{1/2}$)O$_{3}$ using in-situ TEM, providing new insights into chemical ordering effects.

Findings

Discovery of meandering ferroelectric domains.

Observation of domain-wall dynamics near Curie temperature.

Identification of discontinuous phase transition behavior.

Abstract

Pb-based perovskites with multiple cations are fascinating materials showing various phenomena such as high piezoelectric, electromechanical, and relaxor properties. While chemical disordering accompanied by polar nanoregions and nanosized domains is commonly believed to cause the relaxor nature, little is known about ferroelectric microstructures of chemically ordered Pb-based perovskites. In this study, we discovered intriguing meandering ferroelectric domains in chemically ordered ferroelectric Pb(Sc$_{1/2}$Nb$_{1/2}$)O$_{3}$ using in-situ transmission electron microscopy with dark-field imaging. Observation results demonstrate that electric polarization can fluctuate around the [111] direction despite the formation of long-range ordered rhombohedral domains, which results in unique weak relaxor properties. In-situ imaging upon heating successfully reveals the dynamic behavior of domain-wall movements with lattice distortion and paraelectric-ferroelectric phase coexistence in the vicinity of the Curie temperature, indicating a discontinuous phase transition. Our research provides new insights into the effect of chemical ordering on ferroelectric nanodomains.