Anisotropic lattice expansion determined during flash sintering of BiFeO3 by in-situ energy-dispersive X-ray diffraction

Abstract

BiFeO3 has a Curie temperature (TC) of 825 °C, making it difficult to sinter using conventional methods while maintaining the purity of the material, as unavoidably secondary phases appear at temperatures above Tc. Flash sintering is a relatively new technique that saves time and energy compared to other sintering methods. BiFeO3 was flash sintered at 500 °C to achieve 90% densification. In-situ energy dispersive X-ray diffraction (EDXRD) revealed that the material did not undergo any phase transformation, having been sintered well below the TC. Interestingly, anisotropic lattice expansion in the material was observed when the sample was exposed to the electric field.