Coexistence and competition of local- and long-range polar orders in a ferroelectric relaxor

Abstract

We have performed a series of neutron diffuse scattering measurements on a single crystal of the solid solution Pb(Zn${}_{1/3}$Nb${}_{2/3}$)O${}_3$ (PZN) doped with 8% PbTiO${}_3$ (PT), a relaxor compound with a Curie temperature T${}_C\sim 450$ K, in an effort to study the change in local polar orders from the polar nanoregions (PNR) when the material enters the ferroelectric phase. The diffuse scattering intensity increases monotonically upon cooling in zero field, while the rate of increase varies dramatically around different Bragg peaks. These results can be explained by assuming that corresponding changes occur in the ratio of the optic and acoustic components of the atomic displacements within the PNR. Cooling in the presence of a modest electric field $\vec{E}$ oriented along the [111] direction alters the shape of diffuse scattering in reciprocal space, but does not eliminate the scattering as would be expected in the case of a classic ferroelectric material. This suggests that a field-induced redistribution of the PNR has taken place.

Cited by in corpus (4)

• Phase instability induced by polar nanoregions in a relaxor ferroelectric system
• A reassessment of the Burns temperature and its relationship to the diffuse scattering, lattice dynamics, and thermal expansion in the relaxor PMN
• Neutron and X-ray diffraction study of cubic [111] field cooled Pb(Mg1/3Nb2/3)O3
• Response of polar nanoregions in 68%Pb(Mg1/3Nb2/3)O3-32%PbTiO3 to a [001] electric field