Blackett Laboratory, Imperial College London, London, UK.
Sci Rep. 2016 Sep 12;6:32864. doi: 10.1038/srep32864.
Realising the promise of next-generation magnetic nanotechnologies is contingent on the development of novel methods for controlling magnetic states at the nanoscale. There is currently demand for simple and flexible techniques to access exotic magnetisation states without convoluted fabrication and application processes. 360° domain walls (metastable twists in magnetisation separating two domains with parallel magnetisation) are one such state, which is currently of great interest in data storage and magnonics. Here, we demonstrate a straightforward and powerful process whereby a moving magnetic charge, provided experimentally by a magnetic force microscope tip, can write and manipulate magnetic charge states in ferromagnetic nanowires. The method is applicable to a wide range of nanowire architectures with considerable benefits over existing techniques. We confirm the method's efficacy via the injection and spatial manipulation of 360° domain walls in Py and Co nanowires. Experimental results are supported by micromagnetic simulations of the tip-nanowire interaction.
实现下一代磁性纳米技术的承诺取决于开发新型方法来控制纳米尺度上的磁状态。目前需要简单灵活的技术来访问奇异的磁化状态，而无需复杂的制造和应用过程。360°畴壁（磁化的亚稳扭转，将两个具有平行磁化的畴分开）就是这样一种状态，它目前在数据存储和磁振子学中非常感兴趣。在这里，我们展示了一种简单而强大的方法，通过该方法，移动磁荷（由磁力显微镜探针在实验中提供）可以在铁磁纳米线中写入和操纵磁荷状态。该方法适用于广泛的纳米线结构，与现有技术相比具有相当大的优势。我们通过在 Py 和 Co 纳米线中注入和空间操纵 360°畴壁来验证该方法的有效性。实验结果得到了针尖-纳米线相互作用的微磁模拟的支持。
