Department of Physics, University of Alberta, Edmonton, Alberta, Canada.
Science. 2013 Mar 1;339(6123):1051-4. doi: 10.1126/science.1231390. Epub 2013 Jan 17.
Quantitative characterization of intrinsic and artificial defects in ferromagnetic structures is critical to future magnetic storage based on vortices or domain walls moving through nanostructured devices. Using torsional magnetometry, we observe finite size modifications to the Barkhausen effect in the limiting case of a single vortex core interacting with individual pointlike pinning sites in a magnetic thin film. The Barkhausen effect in this limit becomes a quantitative two-dimensional nanoscale probe of local energetics in the film. Tailoring the pinning potential using single-point focused ion beam implantation demonstrates control of the effect and points the way to integrated magneto-mechanical devices incorporating quantum pinning effects.
定量描述铁磁结构中的固有缺陷和人为缺陷对于基于通过纳米结构器件移动的涡旋或畴壁的未来磁存储至关重要。使用扭转磁强计，我们在单个涡旋核与磁性薄膜中的单个点状钉扎点相互作用的极限情况下观察到了巴克豪森效应的有限尺寸修正。在这种极限情况下，巴克豪森效应成为薄膜中局部能量的定量二维纳米探针。使用单点聚焦离子束注入来调整钉扎势，证明了对该效应的控制，并为结合量子钉扎效应的集成磁机械装置指明了方向。
