Performance Enhancement and In Situ Observation of Resistive Switching and Magnetic Modulation by a Tunable Two‐Level System of Mn Dopants in a‐Gallium Oxide‐based Memristor

Purely gallium oxide‐based memristors (GOMRs) show great potentials in resistive random‐access‐memory (RRAM) due to their chemical stability and resistive switching characteristics with Roff/Ron ratios up to 102; indeed, GOMRs with higher Roff/Ron ratios and more functionalities are more expected. In this study, ferromagnetic amorphous gallium oxide (a‐GMO) films with a tunable two‐level system of Mn dopants, i.e., Mn2+ and Mn3+ ions, are prepared by scalable polymer assisted deposition. The Pt/a‐GMO/Pt memristors show a high Roff/Ron ratio of 103, at least one order of magnitude higher than those of previously reported purely GOMRs, thanks to the abundant oxygen vacancies (VOs)‐induced low resistance state and Mn2+‐enhanced high resistance state. Meanwhile, magnetic modulation (MM) is realized electrically in the a‐GOMRs during the RS, through the tuning of bound magnetopolarons (BMPs) by bias voltage‐induced VOs variations, which may be useful for quaternary information coding. Notably, the transition between Mn3+ and Mn2+ions is observed in the GOMRs, which is closely related to the variations of VO concentration and BMP amount, providing an in situ tool to probe the VO‐induced RS and BMP‐dependent MM. The results give insights to Mn‐doped GOMRs and may be useful for design, fabrication, and testing of multifunctional high‐performance RRAMs. Ferromagnetic amorphous gallium oxide (a‐GMO) films are fabricated with a tunable two‐level system of Mn dopants, i.e., Mn2+ and Mn3+ ions. The Pt/a‐GMO/Pt memristors show a high Roff/Ron ratio of 103, at least one order of magnitude higher than those of previously reported purely gallium oxide‐based memristors, thanks to the abundant oxygen vacancies induced low resistance state and Mn2+‐enhanced high resistance state.