The β-to-γ Transition in BiFeO3: A Powder Neutron Diffraction Study

✍ Scribed by Donna C. Arnold; Kevin S. Knight; Gustau Catalan; Simon A. T. Redfern; James F. Scott; Philip Lightfoot; Finlay D. Morrison

• Publisher: John Wiley and Sons
• Year: 2010
• Tongue: English
• Weight: 529 KB
• Volume: 20
• Category: Article
• ISSN: 1616-301X
• DOI: 10.1002/adfm.201000118

✦ Synopsis

Abstract

High‐temperature powder neutron diffraction experiments are conducted around the reported β–γ phase transition (∼930 °C) in BiFeO~3~. The results demonstrate that while a small volume contraction is observed at the transition temperature, consistent with an insulator–metal transition, both the β‐ and γ‐phase of BiFeO~3~ exhibit orthorhombic symmetry; i.e., no further increase of symmetry occurs during this transition. The γ‐orthorhombic phase is observed to persist up to a temperature of approximately 950 °C before complete decomposition into Bi~2~Fe~4~O~9~ (and liquid Bi~2~O~3~), which subsequently begins to decompose at approximately 960 °C.