Micromagnetic simulation of electrochemically deposited Co nanowire arrays for wideband microwave applications

Abstract

We study the magnetic properties of arrays of Co nanowires which exhibit zero bias-field FMR absorptions in a 0-30 GHz range. Columnar arrays of Co nanowires with lengths of 8-15 µm were electrochemically grown using ~20 µm thick anodic alumina membranes with 50 nm pore diameters. Microstructural, static magnetic, and microwave properties of five different nanowire arrays were characterized. The studied Co nanowires present different crystal structure textures and magnetic properties. The static magnetic loop shapes and the ferromagnetic resonance frequencies of the nanowire arrays were correctly reproduced using the Mumax3 micromagnetic software. For each sample input parameters dependent on the XRD and microstructural data,were fine-tuned to allow the best fit of the experimental hysteresis loops and the related microwave spectra. Using this method, it was possible to analyze the rather complex interplay between geometry and magneto-structural features of the different arrays, defining which parameters play a key role in the development of nano-systems with specific microwave properties. Keywords: magnetic properties, Co nanowire arrays, FMR, microwave

Tailoring ferromagnetic resonance properties of cobalt nanowires: effects of shape and magnetocrystalline anisotropies

“…Pasquale et al demonstrated that experimentally determined ferromagnetic resonance properties of cobalt nanowire arrays at room temperature exhibit a very good correspondence with those obtained through micromagnetic simulations conducted at zero Kelvin. 33 Moreover, the results obtained in this study concerning the bulk mode during diameter variation for Co-NWs with an easy-axis MCA closely align with those reported by Yuan et al for high-length nanowires (∼40 μm) with diameters of 60 and 90 nm under zero-field conditions, exhibiting frequency values ranging from approximately 25 to 35 GHz. 34 Similarly, for Co-NWs with an easy-plane MCA, we observed a strong agreement between the azimuthal mode frequencies in high-diameter nanowires (≥100 nm) and the experimental findings reported by Lei et al for nanowires with a diameter of 200 nm under zero-field conditions, showing frequencies of around 20 GHz.…”