On the theory of domain switching kinetics in ferroelectric thin films

TL;DR

This paper presents a theoretical model for polarization switching in ferroelectric thin films, revealing a new distribution function for switching times that aligns better with experimental data and explains the physical mechanisms involved.

Contribution

It introduces a novel 'square of Lorentzian' distribution for switching times, improving upon previous models and accounting for the vector nature of electric fields in ferroelectric domain switching.

Findings

Distribution of switching times is a square of Lorentzian, not Lorentzian.

Model better explains experimental data on switching kinetics.

Physical mechanism of domain switching times is clarified.

Abstract

We investigate theoretically the polarization switching kinetics in ferroelectric thin films. In such substances, the domain walls are pinned by (usually dipole) defects, which are present also in ordered samples as technologically unavoidable impurities. This random interaction with dipole pinning centers results, in particular, in exponentially broad distribution of switching times. Under supposition of low pinning centers concentration, we derive the distribution function of switching times showing that it is not simply Lorentzian (as it was first suggested by Tagantsev et al [\prb, {\bf 66}, 214109 (2002)] ), but is a "square of Lorentzian", which is due to the vector nature of electric field. This improved formalism delivers a better description of available experimental data and elucidates the physical mechanism of domain switching times distribution.