Compositional-induced structural transformation and relaxor ferroelectric behavior in Sr/Nb-modified Bi4Ti3O12 Aurivillius ceramics

This study reports the synthesis of Sr/Nb-modified Bi4Ti3O12 Aurivillius phase, SrxBi4-xTi3-xNbxO12 (x = 0, 0.5, 1, 1.5, and 2) for lead-free relaxor ferroelectric materials using the molten-salt method. The effects of cation substitution (x content) on the structure, morphology, electrical and optical properties was investigated. X-ray diffraction and dielectric measurements revealed that the phase structures of the parent compound Bi4Ti3O12 (x = 0) experienced a gradual transformation from the orthorhombic B2cb phase to the tetragonal I4/mmm phase, for x = 1.5 and 2. Upon increasing the x content, the Curie-Weiss temperature (T-c) and dielectric constant decreased, which are explained in terms of reducing the structural distortion of orthorhombic structure. The cation substitution induced the A-and B-site cation disorder and intensified diffusion and relaxor-ferroelectric behavior. These findings will provide significant impetus for further research on relaxor ferroelectric Aurivillius phases.

Automated summary

This study reports the synthesis of Sr/Nb-modified Bi4Ti3O12 Aurivillius phase using the molten-salt method, and investigates the effects of cation substitution on the properties of the materials. The results show that the phase structure and electrical properties of the materials change with the increase of cation substitution.