Department of Physics , University of Basel , 4056 Basel , Switzerland.
Institut für Experimentelle und Angewandte Physik , Universität Regensburg , D-93040 Regensburg , Germany.
Nano Lett. 2019 Feb 13;19(2):930-936. doi: 10.1021/acs.nanolett.8b04174. Epub 2019 Jan 9.
We present a scanning magnetic force sensor based on an individual magnet-tipped GaAs nanowire (NW) grown by molecular beam epitaxy. Its magnetic tip consists of a final segment of single-crystal MnAs formed by sequential crystallization of the liquid Ga catalyst droplet. We characterize the mechanical and magnetic properties of such NWs by measuring their flexural mechanical response in an applied magnetic field. Comparison with numerical simulations allows the identification of their equilibrium magnetization configurations, which in some cases include magnetic vortices. To determine a NW's performance as a magnetic scanning probe, we measure its response to the field profile of a lithographically patterned current-carrying wire. The NWs' tiny tips and their high force sensitivity make them promising for imaging weak magnetic field patterns on the nanometer-scale, as required for mapping mesoscopic transport and spin textures or in nanometer-scale magnetic resonance.
我们提出了一种基于由分子束外延生长的单个顶端磁化 GaAs 纳米线 (NW) 的扫描磁力传感器。其磁尖端由通过液体 Ga 催化剂液滴的顺序结晶形成的单晶 MnAs 的最后一段组成。我们通过测量其在施加磁场中的弯曲机械响应来表征这种 NW 的机械和磁性特性。与数值模拟的比较允许识别它们的平衡磁化配置，在某些情况下包括磁涡。为了确定 NW 作为磁扫描探针的性能，我们测量了它对光刻图案电流承载线的磁场分布的响应。NW 的微小尖端及其高力灵敏度使它们有望在纳米尺度上成像弱磁场模式，这对于映射介观输运和自旋纹理或纳米尺度磁共振是必需的。
