Temperature-Dependent Phase Transition In Barium Titanate Crystals Probed By Second Harmonic Generation

More and more evidence points out the coexistence of displacive and order-disorder dynamics in the phase transition of barium titanate. Here, we report an initial state determined phase transition in barium titanate by applying second harmonic generation technology and piezoresponse force microscopy (PFM). The out-of-plane PFM results of these barium titanate crystals show the increase in domain walls in the surfaces after annealing, leading to the increase in the second harmonic signal measured. This work directly revealed how the displacive and order-disorder dominate the phase transition and what the role is that the domain wall plays in this process. Published by AIP Publishing.