Unveiling the ac Dynamics of Ferroelectric Domains by Investigating the Frequency Dependence of Hysteresis Loops

We investigated nonequilibrium domain wall dynamics under an ac field by measuring the hysteresis loops of epitaxial ferroelectric capacitors at various frequencies and temperatures. Polarization switching is induced mostly by thermally activated creep motion at lower frequencies, and by viscous flow motion at higher frequencies. The dynamic crossover between the creep and flow regimes unveils two frequency-dependent scaling regions of hysteresis loops. Based on these findings, we constructed a dynamic phase diagram for hysteretic ferroelectric domain dynamics in the presence of ac fields.