We present a critical reexamination of the Landau–Ginzburg–Devonshire (LGD) model for ferroelectric materials that is based on intrinsic nucleation events. Theoretical considerations and a systematic comparison with experiments steered us towards a novel version and calibration of the LGD model relying instead on extrinsic nucleations. We show that the new model can not only improve the agreement with experiments, but also help reconcile the interpretation of polarization reversal in poly-crystalline and epitaxial ferroelectrics.
