Resistive switching characteristics of maghemite nanoparticle assembly on Al and Pt electrodes on a flexible substrate

Resistive switching characteristics of maghemite (γ-Fe2O3) nanoparticle assembly were investigated in structures of top-electrode (Al,Pt)/γ-Fe2O3-NPs (∼ 30 nm-thick)/bottom electrode (Al,Pt) on a flexible polyethersulfone substrate. The assembled NP layer with Al electrodes showed both unipolar and bipolar switchings with abrupt resistance change in multiple levels associated with formation and sequential rupture of conducting filaments, which is ascribed to Fe enrichment by the interfacial reaction. On the other hand, the NP layer with Pt electrodes exhibited memristive switching with hysteresis in current-voltage characteristics dependent on bias polarity, gradually changing the resistance with respect to bias conditions, and preserved resistance until a new state was developed by subsequent biasing. (paper)