Spin transport in 3D Interconnected Co Nanowire Networks

Three-dimensional (3D) magnetic assemblies can host unique topological features and exotic spin textures. Here we report magnetoresistance (MR) studies of interconnected Co nanowire (NW) networks realized using multiple angle ion-tracking and electrodeposition [1]. In a large ensemble of NWs, a typical anisotropic MR behavior was observed during magnetic field sweep, with a minimum near the coercive field. However, when only a few interconnected NWs were measured, multiple kinks and local minima were found, including a significant minimum at a positive field during the positive-to-negative field sweep. Micromagnetic simulations show that this unusual feature is indicative of domain wall (DW) pinning at the NW intersections.  Interestingly, this peak position shifts when the magnitude of the applied current density is varied. This demonstrates the potential that DW motion through the network may be controlled by current to implement multistate memristors. The MR results were compared with magnetic configurations probed by magnetometry, magnetic imaging and small angle neutron scattering. Our results highlight the promise of these networks to be utilized in 3D magnetic memory and memristive devices.

[1] E. Burks et al, Nano Lett., 21, 716 (2021).