Fabrication and Magnetic Behavior of Jellyfish-Like Ni Nanowires Synthesized Using Bilayered Nanoporous Anodic Alumina Templates.

The potential to produce nanostructures with intricate shapes in large quantities holds promise for a range of applications in the fields of nanoelectronics and biomedicine. Here a method for fabricating Ni jellyfish-like nanowires (JFNWs) using bilayered nanoporous anodic alumina templates with through pores of varying diameters in each layer. To assess the capabilities of this method, samples are created with different voltages during the second step of anodization, resulting in distinct geometrical characteristics of the second layer of the template, and subsequently synthesize Ni JFNWs. By employing magnetometry and first-order reversal curve (FORC) method, the magnetic properties are examined and a significant alteration in their magnetic behavior, attributed to the differing shapes of the JFNWs and the magnetostatic interactions within the array, is observed. The study utilizes magnetic force microscopy to evaluate the stray magnetic fields generated by the individual JFNWs and unveils their unusual and asymmetric distribution. Through simulations based on the experimental data, the study analyzes the field- and current-induced domain wall movement in a single JFNW and their array. The findings reveal non-trivial micromagnetic configurations in these structures, including a remarkable 'corkscrew' state, and allow for an examination of the process of magnetization switching.