Tailoring magnetic domain walls in cylindrical nanowires

Cylindrical magnetic nanowires, NWs, are considered promising for technological applications as they offer new ways to design their magnetization reversal processes. They present important advantages such as: the possibility to tailor the domain wall (DW) shape by adjusting the nanowires geometry or anisotropy, the stability of DW during its motion and suppression of Walker breakdown [1-3]. Here we show a way of controlling DW propagation in these one-dimensional nanostructures by specific designs in geometry (i.e., modulations of diameter), or in magnetic anisotropy (i.e., modulations in the composition) [4]. In this way, the modulation will act as pinning center for nucleation, pinning and depinning of DWs. These local variations changes the typical single-domain state present in soft NWs, as well as the mono domain wall-type switching of the magnetization based on the DW nucleation and propagation. A detailed description of the magnetic configuration of individual cylindrical Co-based NWs is presented by combining XMCD-PEEM which allows resolving the surface and the internal magnetic structure of NWs, magneto-optical Kerr effect and micromagnetic simulations.
References:
1. H.-G. Piao et al., Appl.Phys. Lett. 102, 112405 (2013)
2. M. Yan et. al. Phys. Rev. Lett. 104 (2010) 057201
3. D. Reyes et al., NanoLetters 16, 1230(2016)
4. C. Bran et al., J. Mater. Chem. C 4, 978 (2016)