Structure Refinement of the High-Temperature Triclinc Form of BiTaO4 From Neutron Powder Diffraction
P DeSanto, Winnie Wong-Ng, Zhi Yang, Jeremy C. Cook, B H. Toby
The structure of the high-temperature form of BiTaO4 has been refined using neutron powder diffraction data. The unit cell is triclinic, P (Sp. Gr. #2) with a = 7.66312(16) , b = 5.58825(11) , c = 7.78659(16) , ? = 90.0573(10)?, ? = 77.0388(9)?, and ? = 86.4617(9)?. The structure consists of puckered sheets of TaO6 octahedra, similar to those found in ?-BiNbO4. However, the TaO6 octahedra are more regular due to a reduced 2nd order Jahn-Teller effect from Ta5+ relative to Nb5+. Bi coordination also differs significantly from that found in ?-BiNbO4. Thermal analysis indicated conversion of orthorhombic to triclinic BiTaO4 at 1051?C; however, this transition is irreversible and may be dependent upon sample history.
, Wong-Ng, W.
, Yang, Z.
, Cook, J.
and Toby, B.
Structure Refinement of the High-Temperature Triclinc Form of BiTaO<sub>4</sub> From Neutron Powder Diffraction, Chemistry of Materials
(Accessed December 10, 2023)