Non-volatile multi-state magnetic domain transformation in a Hall balance

High performance of the generation, stabilization and manipulation of magnetic skyrmions prompts the application of topological multilayers in spintronic devices. Skyrmions in synthetic antiferromagnets (SAF) have been considered as a promising alternative to overcome the limitations of ferromagnetic skyrmions, such as the skyrmion Hall effect and stray magnetic field. Here, by using the Lorentz transmission electron microscopy, the interconversion between the single domain, labyrinth domain and skyrmion state can be observed by the combined manipulation of electric current and magnetic field in a Hall balance (a SAF with the core structure of [Co/Pt]₄/NiO/[Co/Pt]₄ showing perpendicular magnetic anisotropy). Furthermore, high-density room temperature skyrmions can be stabilized at zero field while the external stimulus is removed and the skyrmion density is tunable. The generation and manipulation method of skyrmions in Hall balance in this study opens up a promising way to engineer SAF-skyrmion-based memory devices.     

电沉积石墨烯防腐涂层的研究进展

石墨烯材料的二维平面结构以及优异的抗渗性使其在防腐领域备受关注,电沉积法可以实现石墨烯片层在涂层中的有序排列,增强涂层对外界腐蚀性电解质的阻隔。简单介绍了电沉积法制备石墨烯涂层的原理,详细综述了近年来以电沉积法制备金属基石墨烯复合涂层和导电聚合物基石墨烯复合涂层的研究进展,分析了石墨烯改善在不同基质涂层的原理。最后,展望了石墨烯、金属和导电聚合物三元复合材料在防腐涂层中的应用,并且对两种复合涂层的优缺点进行了简单的总结。