Influence of oxygen ion elementary diffusion jumps on the electron current through the conductive filament in yttria stabilized zirconia nanometer-sized memristor

Abstract

• Nanometer-sized virtual memristors based on an yttria stabilized zirconia thin film. • Low-frequency flicker noise in the electron current through the conducting filament. • The random motion (drift/diffusion) of oxygen ions/vacancies effect in this current. • Estimates of the root-mean-square value of the current jumps caused by this motion. • The determination of elementary electronic processes in memristor systems. The structure of the electron current through an individual filament of a nanometer-sized virtual memristor consisting of a contact of a conductive atomic force microscope probe to an yttria stabilized zirconia (YSZ) thin film deposited on a conductive substrate is investigated. Usually, such investigation is performed by the analysis of the waveform of this current with the aim to extract the random telegraph noise (RTN). Here, we suggest a new indirect method, which is based on the measurement of the spectrum of the low-frequency flicker noise in this current without extracting the RTN, taking into account the geometrical parameters of the filament. We propose that the flicker noise is caused by the motion (drift/diffusion) of oxygen ions via oxygen vacancies within and around the filament. This allows us to estimate the root mean square magnitude i 0 of the current jumps, which are caused by random jumps of oxygen ions, and the number M of these ions. This is fundamental for understanding the elementary mechanisms of electron current flowing through the filament and resistive switching in YSZ–based memristor devices.