Revealing the mechanism of electric-field-induced phase transition in antiferroelectric NaNbO3

2021/04/01 by

Evolution of the X-ray diffraction reflections during a field-induced antiferroelectric (Pbcm space group) to ferroelectric (P21ma space group) in NaNbO3 ceramics. The phase transition occurred around 8 kV/mm, which was clearly decoupled from the significant polarization switching process that occured around 12 kV/mm.

In our recent publication entitled “Revealing the mechanism of electric-field-induced phase transition in antiferroelectric NaNbO3 by in situ high-energy x-ray diffraction” (Appl. Phys. Lett. 2021, 118, 132903), Zhang et al. utilized in situ high-energy X-ray diffraction and a fast area detector to investigate the structural/microstructural changes and macroscopic electrical/mechanical responses of the antiferroelectric-ferroelectric phase transition in NaNbO3.

This work revealed that the field-induced behavior is divided into three stages, whereby the phase transition is clearly decoupled from the polarization switching process. The evolution of the antiferroelectric/ferroelectric phase fraction as a function of applied field was determined and the first-order nature of the transition was confirmed. The observed decoupling is related to the mechanical stress present at the phase boundary and a detailed three-step mechanism is proposed. This mechanism is significantly different from what is currently known from lead-based systems and can explain multiple previous experimental observations. The current study provides insight into the irreversibility of the antiferroelectric-ferroelectric phase transition in NaNbO3.

Publication

Applied Physics Letters, 118,(13) S. 132903 (2021)

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