Influence of tetragonal platelets on the dielectric permittivity of 0.964Na${}_{1/2}$Bi${}_{1/2}$TiO${}_3$-0.036BaTiO${}_3$

Abstract

We study the temperature-dependent evolution of the octahedral tilt order in a lead-free relaxor ferroelectric and its impact on the ferroelectric properties. Using diffuse neutron scattering on a 0.964Na${}_{1/2}$Bi${}_{1/2}$TiO${}_3$-0.036BaTiO${}_3$ single crystal, we suggest a model for the temperature-dependent nanostructure of this perovskite that features chemically pinned tetragonal platelets embedded in the rhombohedral matrix, often separated by a cubic intermediate phase. Our results show a clear correlation between the squared thickness of the tetragonal platelets and the dielectric permittivity. This is interpreted as a sign for increased polarizability of the strained and distorted lattice at the center of the tetragonal platelets.

25 pages, 12 figures

References in corpus (1)

• The structure of planar defects in tilted perovskites

Cited by in corpus (1)

• Relaxation of dynamically disordered tetragonal platelets in the relaxor ferroelectric $0.964{\mathrm{Na}}_{1/2}{\mathrm{Bi}}_{1/2}{\mathrm{TiO}}_3-0.036{\mathrm{BaTiO}}_3$