Domain wall motion in epitaxial Pb(Zr,Ti)O3 capacitors investigated by modified piezoresponse force microscopy

TL;DR

This study examines the dynamics of domain wall motion in epitaxial Pb(Zr,Ti)O3 capacitors using modified piezoresponse force microscopy, revealing creep behavior and the relationship between domain size and wall speed.

Contribution

It introduces a modified PFM technique combined with switching current measurements to reliably image domain evolution and analyze domain wall creep in epitaxial ferroelectric capacitors.

Findings

Domain wall speed decreases with increasing domain size.

Average domain wall velocity exhibits creep behavior under electric field.

The creep follows an exponential relation with an exponent of 0.9 ± 0.1 and an activation field of about 700 kV/cm.

Abstract

We investigated the time-dependent domain wall motion of epitaxial PbZr0.2Ti0.8O3 capacitors 100 nm-thick using modified piezoresponse force microscopy (PFM). We obtained successive domain evolution images reliably by combining the PFM with switching current measurements. We observed that domain wall speed (v) decreases with increases in domain size. We also observed that the average value of v, obtained under applied electric field (Eapp),showed creep behavior: i.e. <v> ~ exp(-E0/Eapp)^$\mu$ with an exponent $\mu$ of 0.9 $\pm$ 0.1 and an activation field E0 of about 700 kV/cm.