Electric Field Effects on the Diffuse Scattering in PZN-8%PT

TL;DR

This study investigates how external electric fields influence neutron diffuse scattering in PZN-8%PT, revealing anisotropic effects that support the phase-shifted PNR model of relaxor ferroelectrics.

Contribution

It provides experimental evidence on the anisotropic response of diffuse scattering to electric fields, supporting the phase-shifted PNR model in relaxor ferroelectrics.

Findings

Diffuse scattering suppressed transverse to (003) at 400 K with E=2 kV/cm

No change in diffuse scattering transverse to (300) up to 10 kV/cm

External electric field does not induce a macroscopically polarized state in the tetragonal phase

Abstract

We report measurements of the neutron diffuse scattering from a single crystal of the relaxor ferroelectric Pb(Zn_1/3Nb_2/3)O_3 doped with 8% PbTiO_3 (PZN-8%PT) for temperatures 100 K < T < 530 K and electric fields 0 kV/cm < E < 10 kV/cm. The diffuse scattering is strongly suppressed transverse to the (003) Bragg peak at 400 K for E = 2 kV/cm applied along the [001] direction. However, no change in the diffuse scattering is observed transverse to (300), even for field strengths up to 10 kV/cm. Thus the application of an external electric field in the tetragonal phase does not produce a macroscopically polarized state. This unusual behavior can be understood within the context of the Hirota et al. phase-shifted polar nanoregion (PNR) model of the relaxor diffuse scattering, since an electric field E oriented parallel to [001] would remove the shift of the nanoregions along [001] while preserving those along the orthogonal [100] direction.