Electric-field-induced stepwise switching in ferroelectric-antiferroelectric transition

Exploring the electric field-induced ferroelectric-antiferroelectric phase transition dynamics at the dipole scale is important for both understanding the mechanisms and enhancing the energy storage performance. Here, we report two phase transition pathways through stepwise switching during the removal of the electric field by phase-field models. Antiferroelectric seeds remaining under high electric fields expand along the direction of the antiphase boundaries, until the electric field is sufficiently low for thickening. Free energy density distributions reveal that the anisotropic stepwise switching mode is related to the mismatch of electrostatic and elastic energy at the tips of antiferroelectric phases. When the electric field exceeds the critical value, antiferroelectric phase nucleates and isotropically expands at ferroelectric domain boundaries in the form of vortex-antivortex pairs. Different phase transition pathways reveal the underlying mechanism for the change of ferroelectric-antiferroelectric reverse phase transition electric field. Further, compressive strain and defect dipoles can increase the reverse phase transition electric field and enhance energy storage properties. This work could shed light on the dynamics of electric-field-induced phase transition theory and the design of energy storage materials.