Regular ArticleLayered Intergrowth Phases Bi4MO8X (X=Cl, M=Ta and X=Br, M=Ta or Nb): Structural and Electrophysical Characterization
Review articleOpen access

AbstractThe high-temperature structural behavior of the layered intergrowth phase Bi4TaO8Cl, belonging to the Sillén-Aurivillius family, has been studied by powder neutron diffraction. This material is ferroelectric, space group P21cn, at TC<640 K. An order–disorder transition to centrosymmetric space group Pmcn is found around 640 K, which involves disordering of TaO6 octahedral tilts. A second phase transition, of a first-order nature, to space group P4/mmm occurs at a temperature of ∼1038 K. The crystal structures of the bromide analogs Bi4MO8Br (M=Nb, Ta) have also been determined at room temperature; both are isomorphous with Bi4TaO8Cl and exhibit maxima in dielectric constant at temperatures of approximately 588 and 450 K, respectively.

Request full text

References (0)

Cited By (0)

No reference data.
No citation data.
Join Copernicus Academic and get access to over 12 million papers authored by 7+ million academics.
Join for free!