Atomic Visualization of the Phase Transition in Highly Strained BiFeO3 Thin Films with Excellent Pyroelectric Response

Key observation is the reversible phase transition of strained BFO thin films with excellent pyroelectric response. Using in situ HRTEM, the atomic-scale movement of the phase boundary and the origin of the phase transition are revealed. The phase transition involves the migration of the phase boundary, which is a prerequisite for the growth of the T-like phase and requires an intermediate phase (highly distorted R-phase) as a precursor, which was verified using FFT diffraction patterns. This result adds to the understanding of multifunctional complex oxide materials.436