Resonant activation of resistive switching in ZrO2(Y) films

Local resistive switching (RS) in ZrO₂(Y) films on conductive substrates has been studied using Conductive Atomic Force Microscopy (CAFM). Switching was performed by triangle voltage pulses with superimposed a high-frequency (HF) sinusoidal signal applied to the contact of the CAFM probe to the ZrO₂(Y) film (together constituting a nanometer-sized virtual memristor). Earlier, the enhancement of the RS performance has been observed when the HF signal was superimposed onto the switching pulses. The effect was attributed to the resonant activation of the migration of oxygen ions via oxygen vacancies by an external alternating electric field. In the present study, this assumption was confirmed by measuring the frequency dependence of the difference between the probe currents in the low-resistance and high-resistance states with a maximum at about 5 kHz. This frequency corresponds to the characteristic one of the jumps of oxygen ions onto adjacent oxygen vacancies in ZrO₂(Y) at 300 K. The experimental results were compared with the results of simulation based on the Chua model of an ideal memristor. (paper)