Impedance spectroscopy of ferroelectrics: The domain wall pinning element

We introduce an equivalent-circuit element based on the theory of interface pinning in random systems to analyze contribution domain wall motion below coercive field impedance a ferroelectric, as function amplitude [Formula: see text] and frequency applied ac electric field. demonstrate our model bulk (PZT) reference sample then investigate capacitor stacks, containing ferroelectric text]–[Formula: (BCZT) thin films, epitaxially grown by pulsed laser deposition Nb-doped single crystal substrates covered with Au electrodes. Impedance spectra from Hz 1 MHz were collected at different text]. Deconvolution is achieved fitting measured we extract for kV/cm, frequency-dependent permittivity BCZT films obtained fit parameters. From extended Rayleigh analysis, obtain coupling strength 0.187 cm/kV between dielectric nonlinearity dispersion identify domain-wall-motion regimes. Finally, construct schematic diagram regimes discuss corresponding domain-wall dynamics. Our approach can be utilized replace purely phenomenological constant phase elements (CPEs) modeling response ferroelectrics extracting material properties.