Effective control of the domain wall (DW) motion along the magnetic nanowires is of great importance for fundamental research and potential application in spintronic devices. In this work, a series of permalloy nanowires with an asymmetric notch in the middle were fabricated with only varying the width (d) of the right arm from 200 nm to 1000 nm. The detailed pinning and depinning processes of DWs in these nanowires have been studied by using focused magneto-optic Kerr effect (FMOKE) magnetometer, magnetic force microscopy (MFM) and micromagnetic simulation. The experimental results unambiguously exhibit the presence of a DW pinned at the notch in a typical sample with d equal to 500 nm. At a certain range of 200 nm < d < 500 nm, both the experimental and simulated results show that the DW can maintain or change its chirality randomly during passing through the notch, resulting in two DW depinning fields. Those two depinning fields have opposite d dependences, which may be originated from different potential well/barrier generated by the asymmetric notch with varying d.
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机译:有效控制磁纳米线沿畴壁(DW)的运动对于自旋电子器件的基础研究和潜在应用非常重要。在这项工作中,制造了一系列在中间具有不对称缺口的坡莫合金纳米线,仅将右臂的宽度(d)从200 nm更改为1000 nm。通过使用聚焦磁光克尔效应(FMOKE)磁力计,磁力显微镜(MFM)和微磁模拟研究了这些纳米线中DW的详细钉扎和去钉过程。实验结果清楚地表明,在d等于500nm的典型样品中,DW固定在凹口处。在200 simulatednm show 展开▼