Resumen:
Evidence of unipolar resistive switching is observed along the aging process of cylindrical microscale Fe-base alloy/TiO2/Au devices (MIM-cells). In the early stages of aging, under low electric fields, we show evidence of the effect of a blocking barrier (a Schottky-type depletion layer) at the active TiO2/Au interface which is measured in the OFF-state before the set process is triggered. Resistance transients after resets, R-OFF(t), provide a relaxation time that is explained in terms of the drifting processes of oxygen vacancies. In the aged stages under high electric fields, a highly insulating behavior is observed in the OFF-state (before the set is produced) which yields fluctuating values of R-OFF. Under these conditions, we show that a recovery of the blocking barrier is still feasible by inverting the polarity of the applied voltage. Further on, the resistance switching is studied at different voltage sweep rates which provide the maximum rate that is necessary to accomplish with the resistive switching dynamics, in order to allow the diffusion of the mobile species.
