Quantitative Analysis of the Nucleation and Growth of Ferroelectric Domains in Epitaxial Pb(Zr,Ti)0 3 Thin Films

摘要

We determined simultaneously the domain wall speed (v) and the nucleation rate (N) of ferroelectric (FE) domains in 100 nm-thick epitaxial PbZr 0.2Ti0.803 capacitors from successive domain evolution images under various applied electric fields ( Eapp) by using piezoresponse force microscopy. We found that, at a given Eapp, the v and the N values decreased as the switching process proceeded. The averaged domain wall speed < v > was confirmed to follow the Merz's law, < v > oc exp[-(Eo/Eapp)], with an activation field E0 of about 700 kV/cm. Moreover, we found that the nucleation process played a more important role in the FE domain switching at higher fields while domain wall motion mainly contributed to the switching at lower fields.