Tuning the switching time of BiFeO₃ capacitors by electrodes' conductivity

Abstract

The influence of the bottom electrode's resistance on ferroelectric switching kinetics has been investigated in BiFeO3/La0.8Ca0.2MnO3 capacitors with Pt top contacts. Reversible biaxial strain applied using a piezoelectric substrate is employed to control the resistance of manganite bottom electrode. We found strong dependence of both the switching time and the coercive fields on the electrode's resistance. The reason is attributed to the splitting of the applied voltage between the ferroelectric film and the electrode, which becomes more severe with increasing switching speed. This highlights a crucial limitation for fast switching using lower-conductivity electrodes and inspires the external control of switching kinetics via the electrodes' conductivity.