Compliance current controlled volatile and nonvolatile memory in Ag/CoFe₂O₄/Pt resistive switching device

We report on the resistive memory effects of a Ag/CoFe₂O₄/Pt device and a deterministic conversion between volatile and nonvolatile resistive switching (RS) memory through the tuning of current compliance (I _CC). For the smaller I _CC (10⁻⁴ A) the device exhibits volatile RS behavior with an atomically sized conducting filament showing the quantum conductance. For an intermediate I _CC (10⁻² A) nonvolatile bipolar RS behavior is observed, which could originate from the formation and rupture of filament consisting of Ag ions. The high resistance state (HRS) of the device shows a semiconducting conduction mechanism, whereas the low resistance state (LRS) was found to be Ohmic in nature. The temperature dependent resistance studies and magnetization studies indicated that the electrochemical metallization plays a dominant role in the resistive switching process for volatile and nonvolatile modes through the formation of Ag conducting filaments. For higher I _CC (10⁻¹ A) the device permanently switches to LRS. The irreversible RS memory behaviors, observed for higher I _CC, could be attributed to the formation of a thick and stable conducting channel formed of oxygen vacancies and Ag ions. The compliance current controlled resistive switching modes with a large memory window make the present device a potential candidate to pave the way for future resistive switching devices. (paper)