Resistive switching behaviours of Pt/Ni0.5Zn0.5Fe2O4/Pt based on film thickness for memristor applications

In this work, Pt/Ni0.5Zn0.5Fe2O4/Pt (Pt/NZFO/Pt) sandwich structure material with different NZFO film thicknesses were synthesised on an Al2O3 substrate using the pulsed laser deposition method. The dependence of the resistive switching characteristics on the NZFO film thickness was studied in detail, and the resistive switching mechanism was investigated. Structural characterizations confirm that the typical sandwich structure of Pt/NZFO/Pt composite films with a continuous change in thickness from 210 to 600 nm was naturally formed on the Al2O3 substrate. I–V measurements confirmed that the Pt/NZFO/Pt composite films exhibited excellent resistive switching behaviour with an adjustable set/reset voltage, large memory window, and good retention. The resistive switching mechanism was ascribed to the formation and rupture of conducting path by oxygen vacancies. The conduction mechanisms were classified into Ohmic conduction (dominant at a low resistance state and at the lower voltage region of the high resistance state) and Schottky emission (dominant at the higher voltage region in the high resistance state). More interestingly, the resistive switching behavior of Pt/NZFO/Pt can be regulated by the NZFO film thickness to meet the requirements of different potential applications.