Enhanced resistive switching and magnetic properties of Gd-doped NiFe₂O₄ thin films prepared by chemical solution deposition method

Influence of Gd ion doping on resistive switching (RS) and magnetic properties of NiFe₂O₄ (NiFe_2−xGd_xO₄, NFG-x) thin films prepared by chemical solution deposition method was investigated. The 0.075 Gd-doped NiFe₂O₄ based devices exhibited much reliable repeatability, endurance (>500 switching cycles), and good data retention (10⁵ s at 25 and 100 °C) without any significant degradation in their RS performance. Dominant conduction mechanisms in devices were Ohmic conduction at low resistance state and at lower voltage region of high resistance state, while Schottky emission dominated at higher voltage region in high resistance state. The physical mechanism of resistive switching was linked with the formation and rupture of conducting filaments, and the improved stability of the switching parameters for Pt/NFG/Pt devices was attributed to appropriate concentration of oxygen vacancies which can easily minimize randomness for formation/rupture of conductive filaments. Due to variation in concentration of oxygen vacancies, saturation magnetization of the RS device at high resistance state was higher than those at virgin state and low resistance state, and changes of saturation magnetization maintained a stable value of 40% between HRS and LRS of Pt/NFG-0.075/Pt device. Our study indicates that doping rare earth element into ferrite thin films is a viable approach for enhancing resistance switching and magnetic properties.