Resistive switching study on diffusive memristors using electrochemical impedance spectroscopy

Diffusive memristors demonstrate volatile resistive switching powered by the diffusion of silver nanoparticles through the matrix of silicon dioxide. The equivalent circuit of the high resistance state has been studied via electrochemical impedance spectroscopy for two types of devices which demonstrate either analog or abrupt switching characteristics. It was found that the resistance component has a relatively good agreement with the differential resistance obtained from the I-V curves, whereas the capacitance visibly increases in the analog switching devices with increasing bias voltage as its conductive precursor filament starts forming with increasing voltage and redistribution of silver nanoparticles starts to occur at the top electrodes. Such an effect is not observed for abrupt switching device, which rapidly enters its conductive state for a small increase in bias voltage. This experimental approach allows for the identification of different types of electrical circuit behaviors in a memristive device, even before resistive switching takes place.