The Technique to Characterize Irreversible Domain Motion in Ferroelectric Thin Films in a Large Time Scale

Abstract

Ferroelectric thin films after the field keep a large remanent polarization, i.e., the domain motion is irreversible. Obviously, the accessing speed of the ferroelectric memories depends on the domain switching time traditionally estimated from the position of a peaked current transient with time varying with the applied voltage. However, the circuit parasitics affects the shape of switching current transient and thus the accuracy of estimated domain switching speed. After simulation of the current transient with various circuit RC time constants and input pulse rising times, and a correct method is suggested, and the intrinsic field E dependence of domain switching speed ν at temperature T =77.6- 320 K is extracted. The dependence obeys the Merz's law ν∝exp(- α/E) with the activation field α∝1/T according to the domain nucleation model, suggestive of the common physics of domainswitching kinetics between the bulk ceramics and thin films.