Estimation of film-electrode contact resistance and domain switching time from ferroelectric polarization-voltage hysteresis loops

The large resistance of bottom oxide electrodes in epitaxial/polycrystalline ferroelectric thin films and the existence of interfacial passive layers between the film and top/bottom electrode can affect domain switching speed as well as coercive-voltage estimation from polarization-voltage (P-V) hysteresis loops. With the measurements of P-V hysteresis loops at different frequencies, we estimated the intrinsic ferroelectric coercive voltage as well as the contact resistance either in epitaxial Au/Pb(Zr,Ti)O3/Fe2O3 thin-film capacitors with the poor conductance of Fe2O3 bottom electrodes or in polycrystalline Pt/Al2O3/Pb(Zr,Ti)O3/Ir capacitors with random grain orientations where the ultrathin Al2O3 amorphous layer can mimic the interfacial-layer behavior. The averaged domain switching times at different frequencies were also obtained in both films from P-V hysteresis loops without the assistance of traditional square pulse characterization.