Unexpected phase transition sequence in the ferroelectric Bi₄Ti₃O₁₂.

ABSTRACT: The high-temperature phase behaviour of the ferroelectric layered perovskite Bi₄Ti₃O₁₂ has been re-examined by high-resolution powder neutron diffraction. Previous studies, both experimental and theoretical, had suggested conflicting structural models and phase transition sequences, exacerbated by the complex interplay of several competing structural instabilities. This study confirms that Bi₄Ti₃O₁₂ undergoes two separate structural transitions from the aristotype tetragonal phase (space group I4/mmm) to the ambient-temperature ferroelectric phase (confirmed as monoclinic, B1a1). An unusual, and previously unconsidered, intermediate paraelectric phase is suggested to exist above T _C

SUBMITTER: Guo YY 

PROVIDER: S-EPMC6503926 | biostudies-literature | 2019 May

REPOSITORIES: biostudies-literature