Structural stability of multiferroic BiFeO₃

Abstract

Multiferroic BiFeO₃ was fabricated via a high pressure of 5 GPa at 900 °C. The crystal structure of the BiFeO₃ ceramic was determined by X-ray diffraction (XRD) to be a rhombohedral perovskite with a space group of R3c. The temperature dependence of XRDs was collected down to 5 K under ambient pressure that showed no structure phase transition. The structural evolution of BiFeO₃ under high pressures up to 56.6 GPa was studied at room temperature using a diamond anvil cell combined with synchrotron radiation XRD. A possible phase transition was proposed at around 10 GPa. The bulk modulus was estimated to be B ₀=97.3(7) GPa in the low-pressure range.

Keywords:

• multiferroics
• BiFeO₃ perovskite
• synchrotron radiation
• equation of state

Acknowledgements

This work was sponsored by the Ministry of Sciences and Technology of China.