Three-Dimensional Magnetic Nanostructures Grown by Focused Electron Beam Induced Deposition (FEBID)*

The fabrication of three-dimensional (3D) magnetic nanostructures is currently a central topic in nanomagnetism [1]. Ferromagnetic nanowires (NWs) and nanotubes (NTs) are potential candidates for magnetic data storage, logic and sensing, and Focused Electron Beam Induced Deposition (FEBID) could play a crucial role in the fabrication of these architectures [2].
We have developed a new approach to grow core-shell heterostructures by FEBID [3], obtaining Co@Pt and Fe@Pt NWs, and Co NTs [4]. In addition, annealing treatments of Co NWs have been found to increase metal purity, crystallinity and magnetic induction [5].
Furthermore, we report on the fabrication of Magnetic Force Microscopy (MFM) tips by FEBID, showing great performance. Tailored Co and Fe MFM tips have been tested, both in ambient conditions and liquid environment, getting outstanding mechanical stability, resolution and sensitivity [6,7]. In particular, Fe tips with a 7 nm-wide sharp end exhibit low sample-tip magnetic interaction, which has been useful to measure complex magnetic states such as skyrmions [7].

[1] Fernández-Pacheco, A. et. al., Sci. Rep. 3, 1492 (2013).
[2] Pablo-Navarro, J. et. al., J. Phys. D 50, 18LT01 (2017).
[3] Pablo-Navarro, J. et. al., Nanotechnology 27, 285302 (2016).
[4] Pablo-Navarro, J. et. al., manuscript in preparation.
[5] Pablo-Navarro, J. et. al., ACS Appl. Nano Mater. 1, 38 (2018).
[6] Jaafar, M.; Asenjo, A.; De Teresa, J. M.; Pablo-Navarro, J. et. al., Spanish Patent P201731292.
[7] Berganza, E.; Jaafar, M.; Goiriena, M.; Pablo-Navarro, J. et. al., arxiv:1803.08768.