  Controlled bipolar resistive switching (BRS) has been observed in
nanostructured CoFe2O4 films using Al(aluminum)/CoFe2O4/FTO(fluorine-doped tin
oxide) device. The fabricated device shows electroforming-free uniform BRS with
two clearly distinguished and stable resistance states without any application
of compliance current (CC), with a resistance ratio of high resistance state
(HRS) and low resistance state (LRS) > 102. Small switching voltage (< 1 volt)
and lower current in both the resistance states confirms the fabrication of low
power consumption device. In the LRS, the conduction mechanism was found to be
of Ohmic in nature, while the high-resistance state (HRS/OFF state) was
governed by space charge-limited conduction mechanism, which indicates the
presence of an interfacial layer with imperfect microstructure near the top
Al/CFO interface. The device shows nonvolatile behavior with good endurance
properties, acceptable resistance ratio, uniform resistive switching due to
stable, less random filament formation/rupture and a control over the resistive
switching properties by choosing different stop voltages, which makes the
device suitable for its application in future nonvolatile resistive random
access memory (ReRAM).
