A two-component model of the neutron diffuse scattering in the relaxor ferroelectric PZN-4.5%PT

TL;DR

This study investigates neutron diffuse scattering in the relaxor ferroelectric PZN-4.5%PT, revealing distinct polarization components and their responses to electric fields, with insights into their dynamic and static behaviors across temperatures.

Contribution

Introduces a two-component model distinguishing <100> and <110> polarizations contributing to diffuse scattering in PZN-4.5%PT.

Findings

<110> polarizations show little response to [001] field.

<100> polarizations are partially suppressed by the field below T_C.

Diffuse scattering becomes mostly static at 200 K.

Abstract

We report measurements of the neutron diffuse scattering in a single crystal of the relaxor ferroelectric material 95.5%Pb(Zn$_{1/3}$Nb$_{2/3}$)O$_3$-4.5%PbTiO$_3$ (PZN-4.5%PT). Our results suggest that the nanometer scale structure in this compound exhibits both $<100>$ and $<110>$ polarizations, which contribute to different portions of the total diffuse scattering intensity. These contributions can be distinguished by the differing responses to an electric field applied along [001]. While diffuse scattering intensities associated with $<110>$ (T2-type) polarizations show little to no change in a [001] field, those associated with $<100>$ (T1-type) polarizations are partially suppressed by the field at temperatures below the Curie temperature \emph{T$_C$} $\sim 475$ K. Neutron spin-echo measurements show that the diffuse scattering at (0.05,0,1) is largely dynamic at high temperature and gradually freezes on cooling, becoming mostly static at 200 K.