Empa, Swiss Federal Laboratories for Materials Science and Technology , CH-8600 Dübendorf , Switzerland.
Center for Nanoscale Science and Technology , National Institute of Standards and Technology , Gaithersburg , Maryland 20899 , United States.
Nano Lett. 2018 Apr 11;18(4):2263-2267. doi: 10.1021/acs.nanolett.7b04802. Epub 2018 Mar 19.
Mallinson's idea that some spin textures in planar magnetic structures could produce an enhancement of the magnetic flux on one side of the plane at the expense of the other gave rise to permanent magnet configurations known as Halbach magnet arrays. Applications range from wiggler magnets in particle accelerators and free electron lasers to motors and magnetic levitation trains, but exploiting Halbach arrays in micro- or nanoscale spintronics devices requires solving the problem of fabrication and field metrology below a 100 μm size. In this work, we show that a Halbach configuration of moments can be obtained over areas as small as 1 μm × 1 μm in sputtered thin films with Néel-type domain walls of unique domain wall chirality, and we measure their stray field at a controlled probe-sample distance of 12.0 ± 0.5 nm. Because here chirality is determined by the interfacial Dyzaloshinkii-Moriya interaction, the field attenuation and amplification is an intrinsic property of this film, allowing for flexibility of design based on an appropriate definition of magnetic domains. Skyrmions (<100 nm wide) illustrate the smallest kind of such structures, for which our measurement of stray magnetic fields and mapping of the spin structure shows they funnel the field toward one specific side of the film given by the sign of the Dyzaloshinkii-Moriya interaction parameter D.
马林斯关于某些平面磁结构中的自旋纹理可以在平面一侧增强磁通,而在另一侧削弱磁通的想法,导致了所谓的哈勃阵列的永磁体配置的出现。这些应用的范围从粒子加速器和自由电子激光器中的摆动磁铁到电动机和磁悬浮列车,但要在微纳尺度的自旋电子学器件中利用哈勃阵列,就需要解决在 100μm 以下尺寸的制造和场计量问题。在这项工作中,我们表明,在具有独特畴壁手性的奈尔型畴壁的溅射薄膜中,可以在小至 1μm×1μm 的区域中获得哈勃配置的磁矩,并且我们在 12.0±0.5nm 的受控探针-样品距离下测量了它们的杂散场。因为这里的手性是由界面 Dyzaloshinkii-Moriya 相互作用决定的,所以场的衰减和放大是这种薄膜的固有特性,允许根据适当的磁畴定义进行灵活的设计。斯格明子(<100nm 宽)说明了这种结构中最小的一种,我们对杂散磁场的测量和自旋结构的映射表明,它们将磁场引导到由 Dyzaloshinkii-Moriya 相互作用参数 D 的符号决定的薄膜的特定一侧。
Nano Lett. 2018-3-19
ACS Nano. 2021-3-23
Nat Commun. 2017-5-19
Nat Commun. 2015-3-23
Phys Rev Lett. 2020-5-22
Adv Mater. 2015-5-28
Adv Mater. 2021-10