title: Ferroelectric-paraelectric transition in BiFeO3: crystal structure of the orthorhombic beta phase.
abstract: A detailed investigation using variable temperature powder neutron diffraction demonstrates that BiFeO3 undergoes a phase transition from the ferroelectric alpha phase (rhombohedral, R3c) to a paraelectric beta phase (orthorhombic, Pbnm) between 820 degrees C and 830 degrees C. Coexistence of both phases over a finite temperature interval, together with abrupt changes in key structural parameters, confirms that the transition is first order. The beta phase corresponds to a GdFeO3-type perovskite structure.
authors.affiliation: School of Chemistry, University of St. Andrews, North Haugh, St. Andrews, Fife, KY16 9ST, United Kingdom.
authors.forename: Donna C
authors.initials: DC
authors.lastname: Arnold
authors.forename: Kevin S
authors.initials: KS
authors.lastname: Knight
authors.forename: Finlay D
authors.initials: FD
authors.lastname: Morrison
authors.forename: Philip
authors.initials: P
authors.lastname: Lightfoot