Spatially Resolved Mapping of Local Polarization Dynamics in an Ergodic Phase of Ferroelectric Relaxor

TL;DR

This study uses time-resolved Piezoresponse Force Microscopy to map local polarization relaxation in a relaxor ferroelectric, revealing nanoscale inhomogeneities and differences from macroscopic behavior.

Contribution

It provides the first spatially resolved mapping of polarization dynamics in an ergodic phase of relaxor ferroelectrics, highlighting nanoscale heterogeneity.

Findings

Local relaxation follows stretched exponential behavior with beta~0.4.

Presence of 100-200 nm regions with different relaxation speeds.

Nanoscale mapping of Vogel-Fulcher temperatures.

Abstract

Spatial variability of polarization relaxation kinetics in relaxor ferroelectric 0.9Pb(Mg1/3Nb2/3)O3-0.1PbTiO3 is studied using time-resolved Piezoresponse Force Microscopy. Local relaxation attributed to the reorientation of polar nanoregions is shown to follow stretched exponential dependence, exp(-(t/tau)^beta), with beta~~0.4, much larger than the macroscopic value determined from dielectric spectra (beta~~0.09). The spatial inhomogeneity of relaxation time distributions with the presence of 100-200 nm "fast" and "slow" regions is observed. The results are analyzed to map the Vogel-Fulcher temperatures on the nanoscale.