Statistical switching kinetics in ferroelectrics

By assuming a more realistic nucleation and polarization reversal scenario we build a new statistical switching model for ferroelectrics, which is different from either the Kolmogorov-Avrami-Ishibashi (KAI) model or the Nucleation-Limited-Switching (NLS) model. After incorporating a time-dependent depolarization field this model gives a good description about the retardation behavior in polycrystalline thin films at medium or low fields, which can not be described by the traditional KAI model. This model predicts correctly n=1 for polycrystalline thin films at high Eappl or ceramic bulks in the ideal case.

💡 Research Summary

The paper addresses a long‑standing discrepancy between experimental observations of ferroelectric (FE) switching in polycrystalline thin films and the predictions of the classical Kolmogorov‑Avrami‑Ishibashi (KAI) model as well as the more recent Nucleation‑Limited‑Switching (NLS) model. The authors argue that both traditional frameworks rely on oversimplified assumptions: KAI assumes a constant nucleation rate and uniform domain growth, while NLS treats nucleation as a Poisson process but neglects the dynamic influence of the depolarization field that arises during switching. To overcome these limitations, the authors construct a new statistical switching model that explicitly incorporates (i) a time‑ and field‑dependent nucleation rate and (ii) a time‑varying depolarization field (E_dep) generated by already switched regions and interfacial charge accumulation.

The total effective field acting on unswitched domains is defined as E_total(t) = E_appl – E_dep(t). The nucleation rate is expressed as R(t) = R₀ exp