A Neutron Elastic Diffuse Scattering Study of PMN

TL;DR

This study uses elastic diffuse neutron scattering to analyze polar nanoregions in the relaxor ferroelectric PMN, revealing temperature-dependent growth of these regions even below the Curie temperature.

Contribution

It provides detailed neutron scattering data on the shape and temperature evolution of diffuse scattering in PMN, highlighting the persistent growth of polar nanoregions below T_C.

Findings

Diffuse scattering has a butterfly shape near (100) Bragg peak.

Size of polar nanoregions increases with cooling.

Diffuse intensity grows even below the Curie temperature.

Abstract

We have performed elastic diffuse neutron scattering studies on the relaxor Pb(Mg$_{1/3}$Nb$_{2/3}$)O$_3$ (PMN). The measured intensity distribution near a (100) Bragg peak in the (hk0) scattering plane assumes the shape of a butterfly with extended intensity in the (110) and (1$\bar{1}$0) directions. The temperature dependence of the diffuse scattering shows that both the size of the polar nanoregions (PNR) and the integrated diffuse intensity increase with cooling even for temperatures below the Curie temperature $T_C \sim 213$ K.