Enhanced magnetic modulation in NiO-based memory device through ionic liquid pre-treatment

摘要

The electrical manipulation of magnetism is of particular importance owing to its potential applications in low-power memory devices and spintronics. In this study, we demonstrate enhanced magnetic modulation and an increased exchange bias field (H-EB) in NiO films pretreated with ionic liquid (IL), which we refer to as IL-NiO films. The saturation magnetization of the IL-NiO film in the low-resistance state (LRS) is more than 2.5 times than that in the high-resistance state; this value is more than 80% higher than that of the NiO film without IL pretreatment (As-NiO). In addition, the H-EB value of the IL-NiO film is more than 140% higher than that of the As-NiO film. Further analysis indicates that oxygen vacancies and metallic Ni-0 are introduced into the NiO film during the IL pretreatment process, which results in the formation of thicker ferromagnetic Ni conductive filaments (CFs) after the set process. These thicker Ni CFs enhance the magnetism of the IL-NiO film and increase the coupling area between the ferromagnetic Ni and antiferromagnetic NiO in the LRS, thus leading to a larger magnetic modulation and higher H-EB in the IL-NiO film. We believe that our findings can significantly contribute to further advancements in memory devices and allied applications.