Piezoelectric Properties of BiFeO₃ Exposed to High Temperatures

BiFeO3 is a ferroelectric with a Curie temperature of 830 C-degrees, however, its piezoelectric performance at high temperature remains unclear. The current work reveals a disappearance/recovery of piezoelectricity in BiFeO3 at elevated temperature and upon cooling. In particular, that temperature is strongly frequency-dependent and ranges from 280 to 430 C-degrees between 0.5 and 140 Hz, respectively. Meanwhile, in situ and ex situ X-ray diffraction and piezoresponse microscope analysis demonstrate thermally-resistant domain texture to temperatures as high as 750 C-degrees. This demonstrates that the piezoelectricity of BiFeO3 is strongly influenced by its resistance/conductance variations due to charge carrier motion limiting the operational frequency. The investigation enhances the understanding of BiFeO3 complex piezoelectric behavior at various temperatures, offering insights into its potential applications.