Polarization switching properties of spray deposited CsNO3: PVA composite films

Statistical electric field and switching time distributions in PZT 1Nb2Sr ceramics: Crystal- and microstructure effects

“…[3][4][5][6][7][8][9][10] Nucleation and growth of reversed domains are alternatively considered to both require time to become effective for domain switching and related polarization reversal. The second concept favours models, comprising the statistical approach, [11][12][13][14][15][16][17][18][19][20] which are based on the assumption that conditions for switching given by the local environment are different in different areas of the ceramics, which leads to a distribution of switching times. The feature common to these models can be summarized by the intrinsic randomness (IR) of the local conditions for switching.…”

“…Accordingly, the Lorentzian distribution of local random fields was used to describe the polarization reversal in thin ferroelectric films. 12,16,17 Alternatively, a Gaussian distribution of local random fields was applied to describe the dispersive a)…”

“…23 Further development of the IR approach resulted in a concept, named the inhomogeneous field mechanism (IFM) model, 15,18 which leaves the form of the statistical field distribution a priori unspecified, while at the same time it provides a calculation scheme which allows for the computation of this distribution from the experimental data. In contrast to the other IR models, 12,16,17,19 the IFM model tries to relate the non-uniform switching behaviour to the random spatial distribution of the applied electric field. This procedure provides a chance to identify patterns in the field distributions that are typical for specific structural and microstructural features or the materials state and to correlate the shape and parameters of the field distribution with the materials characteristics.…”

“…Additionally, this analysis allows for the investigation of the microscopic characteristics of the local polarization switching, such as the dependence of the local switching time sðEÞ on the value of the local electric field E. The other details of the microscopic switching process are neglected in the IMF model by assuming that switching of a local region occurs instantly as soon as the poling time exceeds respective sðEÞ. An essential limitation of the IMF concept 15,18 and of the other IR models 12,16,17,19 is that the spatial random field distribution is assumed to be static thus neglecting contribution of the time-dependent depolarization fields which develop in the course of polarization switching. Recent self-consistent simulations of polarization switching in bulk polycrystalline ferroelectrics show, however, that account of field-mediated polarization correlations leads to a strong reduction of the local depolarization fields thus supporting the static IMF concept.…”

Universal Polarization Switching Behavior of Disordered Ferroelectrics

“…Although field‐induced switching of polarization in ferroelectrics is a key process for the functioning of many devices, its essential features still elude understanding. Global polarization reversal is described mostly in one of two ways: either as a uniform random nucleation of reversed domains according to the Kolmogorov–Avrami–Ishibashi (KAI) model1–3 with a single field‐dependent switching time τ or as a superposition of responses of numerous regions exhibiting independent switching kinetics,4–8 characterized by a broad distribution of switching times g ( τ ). From the microscopic point of view, local polarization reversal proceeds by few universal mechanisms common for rather different ferroics 9.…”