Doping Mn ions at Co sites to improve resistive switching property of inverse spinel CoFe2O4 resistive random access memory devices

Abstract

In this study, Mn-doped CoFe₂O₄ thin films were prepared by a sol–gel spin-coating method on Pt/Ti/SiO₂/Si substrates for resistive memory application. It was confirmed that Mn ions were doped into Co ion sites. The Mn_xCo_1-xFe₂O₄ thin films with Pt top and bottom electrodes have good resistive switching (RS) properties, such as relatively low forming voltage distribution and narrow Set/Reset voltage distribution, good cycling durability and time retention, especially when Mn doping content x is 0.15. The conduction mechanisms are ohmic behavior in the low-resistance state and Schottky emission in the high-field region in the high-resistance state. The RS mechanism can be explained through formation and fracture of oxygen vacancy filaments. The saturation magnetization strength of manganese-cobalt ferrite films is increased after electro-forming process compared to the Fresh state, which is attributed to the change in oxygen vacancy concentration. This work demonstrates the potential of Mn-doped CoFe₂O₄ films to be used in resistive random access memory.