Temperature independent diffuse scattering and elastic lattice deformations in relaxor PbMg1/3Nb2/3O3

TL;DR

This study investigates diffuse neutron scattering in relaxor PbMg1/3Nb2/3O3, revealing temperature-independent elastic diffuse components linked to lattice deformations, with anisotropic scattering explained by Huang scattering formalism.

Contribution

It demonstrates that elastic diffuse scattering in relaxor PbMg1/3Nb2/3O3 can be described by Huang scattering from mesoscopic lattice deformations, independent of temperature.

Findings

Diffuse scattering is highly anisotropic in low-symmetry zones.

Elastic diffuse component is temperature independent.

Weak satellite maxima are resolution effects.

Abstract

The results of diffuse neutron scattering experiment on PbMg1/3Nb2/3O3 single crystal above the Burns temperature are reported. It is shown that the high temperature elastic diffuse component is highly anisotropic in low-symmetry Brillouin zones and this anisotropy can be described using Huang scattering formalism assuming that the scattering originates from mesoscopic lattice deformations due to elastic defects. The qualitative agreement between this model and the experimental data is achieved with simple isotropic defects. It is demonstrated that weak satellite maxima near the Bragg reflections can be interpreted as the finite resolution effect.