Bipolar and tri-state unipolar resistive switching behaviors in Ag/ZnFe2O4/Pt memory devices

摘要

We report on the co-existence of bipolar and unipolar resistive switching behaviors in Ag/ZnFe2O4/Pt structures of which the ZnFe2O4 layer was fabricated by a chemical solution deposition method. The memory devices show reproducible and stable bipolar resistive switching, tri-state unipolar resistive switching under only applied negative bias voltage, and unipolar resistive switching transited from bipolar resistive switching with different electroforming conditions. Excellent switching cycling in both unipolar resistive switching and bipolar resistive switching is demonstrated. Based on the conducting filament model, electrochemical metallization effect has been proposed to explain the bipolar resistive switching behavior, whereas the unipolar resistive switching behavior is attributed to electrochemical metallization effect and thermochemical effect.