Identifying phase transition behavior in Bi1/2Na1/2TiO3-BaTiO3 single crystals by piezoresponse force microscopy

Using piezoresponse force microscopy (PFM) and Raman spectroscopy, we studied the local temperature-dependent piezoelectric properties and phase structures of 0.95(Bi0.5Na0.5)TiO3-0.05BaTiO3 (BNT-BT) single crystals. Local-area PFM revealed non-ergodic relaxor behavior around 160 °C. Switching spectroscopy-PFM (SS-PFM) results also supported the transition around 160 °C, with a gradual decrease in hysteresis width and nucleation bias. Moreover, Raman spectroscopy provided structural evidence of a phase transition in the same temperature region. These results are consistent with other theories of phase transitions in BNT-BT-based materials and verify the existence of a phase transition from a non-ergodic relaxor to ergodic relaxor of BNT-5.0%BT near 160 °C.