Improved unipolar resistive switching characteristics of Au-doped nickel ferrite magnetic thin films for nonvolatile memory applications

• Published in: Journal of alloys and compounds 2018-01, Vol.732, p.573-584
• Main Authors: Hao, Aize, Ismail, Muhammad, He, Shuai, Qin, Ni, Huang, Wenhua, Wu, Jiang, Bao, Dinghua
• Format: Article
• Language: English
• Subjects: Computer memory; Correlation analysis; Doping; Electroforming; Electronic transport; Ferrites; High resistance; Low resistance; Magnetic films and multilayers; Magnetic measurements; Magnetic properties; Magnetic saturation; Magnetic thin films; Memory devices; Nickel ferrites; Oxygen; Scanning and transmission electron microscopy; Silicon dioxide; Silicon substrates; Studies; Switching; Thin films; Vacancies
• ISSN: 0925-8388; 1873-4669
• DOI: 10.1016/j.jallcom.2017.10.251

Au-doped nickel ferrite (NiFe2O4-Au, NFO-Au) magnetic thin films were prepared on Pt/Ti/SiO2/Si substrates by a chemical solution deposition method to explore the effect of Au doping on unipolar resistive switching (RS) behavior. Experimental results reveal that 1% Au doped NFO film demonstrated considerably optimum switching parameters such as lower electroforming voltage, narrow distribution of SET/RESET voltages, good cycle-to-cycle endurance (103 cycles) and long data retention (105 s at 125 °C) as compared to NFO and Au-(0.5% and 2%) doped NFO films. The improved performance is attributed to suppressing of randomness of oxygen vacancies based filament by Au doping. Current transport conduction mechanisms are found to be Ohmic in low resistance state and Schottky emission in high resistance state. Physical model concerns for the rupture and formation of Au atoms assisted conductive filament inside the Au-doped NFO films based on the thermal effect of oxygen vacancies. Magnetic properties correlated with RS were measured and analyzed. The variation of saturation magnetization with different resistance state may be attributed to Au-doping induced different oxygen vacancies concentrations and make the conversion of valence states of Fe3+ and Fe2+ ions in octahedral sites easier. Our results provide a pathway towards the applications in nonvolatile RS memory and magnetoelectronic coupling devices. •Improved resistive switching parameters were obtained through Au-doping in ferrite films.•Au-doping in nickel ferrite films effectively suppresses the randomness of conductive filament.•Relationship between resistive switching, magnetic property, and conductive filaments was discussed.