Optimum resistive switching characteristics of NiFe2O4 by controlling film thickness

Highlights: • The Pt/NiFe₂O₄/Pt capacitor-like memory device switches the highly distinguishable, reversible and reproducible with an optimum 200 nm thick insulating layer. • The oxygen vacancies (V_O) were preferentially segregated along with the grain boundaries (GBs) which could effectively constitute a percolation path for the leakage current passing. • Such a simple method with manipulating thin film thickness was demonstrated in this study. In this work, a simple and effective method with different thicknesses in the ranges of 100–300 nm of insulating layer was investigated to enhance the performance of resistive switching behavior in polymetallic oxide-based spinel nickel ferrite (NiFe₂O₄) resistive switching memristor. The Pt/NiFe₂O₄/Pt capacitor-like device with an optimum 200 nm thick insulating layer has been found to operate at room temperature in unipolar resistive switching (URS) mode and with narrow distribution and less fluctuation on endurance property, and then switches the highly distinguishable (ON/OFF ratio >100 times), reversible and reproducible between the ON and OFF states. The Pt/NiFe₂O₄/Pt symmetric layered structure using a designed 200 nm insulating layer without any further post-deposition annealing demonstrates higher stability without any inter-overlap signal between high resistive state (HRS) and low resistive state (LRS) transition. The optimum characteristic in NiFe₂O₄ operating control is without any abnormal resistive switching behavior. Such a designed insulating layer with critical thickness plays a key role to enhance the comprehensive performance of the switching behavior, which could be a simple and effective method with a high successful rate of fabrication for requirements of industrial technology. This work could provide a solid foundation in multi-functional devices and make a stepping forward to the universal memristor with an extremely low-temperature process in the future.