Realization of Complex-Shaped Magnetic Nanotubes with 3D Printing and Electrodeposition

The expansion of nanomagnetism to the third dimension leads to phenomena such as curvature-induced magnetochirality and anisotropy, which can significantly influence the behavior of magnetic textures. One of the most promising systems is the magnetic nanotube – where intrinsic curvature effects are present. However, studies of magnetic nanotubes remain limited to straight systems, and little is known about the influence of 3D geometries. In this work, three dimensional (3D) complex-shaped nanotubes are fabricated by combining nanoprinting with the conformal deposition of magnetic films. Specifically, 3D conductive non-magnetic tungsten scaffolds are fabricated using focused electron beam induced deposition and subsequently coated with a nickel magnetic shell, resulting in complex-shaped magnetic nanotubes whose geometry can be controlled by tuning the electron-beam parameters and electrodeposition conditions. Performing X-ray microscopy revealed that nanotubes of various geometries host a vortex-like azimuthal state, and that the energy landscape of the magnetic configuration can be tailored geometrically. Specifically, the pinning of magnetic domain walls at curved vertices is observed experimentally and confirmed with micromagnetic simulations, offering geometrical control of magnetic configurations in nanotube architectures. This approach provides a new pathway to fabricate and study complex 3D core-shell magnetic structures, facilitating experimental investigations of their fundamental properties, key for the next-generation of spintronic devices.