Nanomaterials (Jun 2018)

Fabrication of Scaffold-Based 3D Magnetic Nanowires for Domain Wall Applications

  • Dédalo Sanz-Hernández,
  • Ruben F. Hamans,
  • Johannes Osterrieth,
  • Jung-Wei Liao,
  • Luka Skoric,
  • Jason D. Fowlkes,
  • Philip D. Rack,
  • Anna Lippert,
  • Steven F. Lee,
  • Reinoud Lavrijsen,
  • Amalio Fernández-Pacheco

DOI
https://doi.org/10.3390/nano8070483
Journal volume & issue
Vol. 8, no. 7
p. 483

Abstract

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Three-dimensional magnetic nanostructures hold great potential to revolutionize information technologies and to enable the study of novel physical phenomena. In this work, we describe a hybrid nanofabrication process combining bottom-up 3D nano-printing and top-down thin film deposition, which leads to the fabrication of complex magnetic nanostructures suitable for the study of new 3D magnetic effects. First, a non-magnetic 3D scaffold is nano-printed using Focused Electron Beam Induced Deposition; then a thin film magnetic material is thermally evaporated onto the scaffold, leading to a functional 3D magnetic nanostructure. Scaffold geometries are extended beyond recently developed single-segment geometries by introducing a dual-pitch patterning strategy. Additionally, by tilting the substrate during growth, low-angle segments can be patterned, circumventing a major limitation of this nano-printing process; this is demonstrated by the fabrication of ‘staircase’ nanostructures with segments parallel to the substrate. The suitability of nano-printed scaffolds to support thermally evaporated thin films is discussed, outlining the importance of including supporting pillars to prevent deformation during the evaporation process. Employing this set of methods, a set of nanostructures tailored to precisely match a dark-field magneto-optical magnetometer have been fabricated and characterized. This work demonstrates the versatility of this hybrid technique and the interesting magnetic properties of the nanostructures produced, opening a promising route for the development of new 3D devices for applications and fundamental studies.

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