Stress tunable dynamic susceptibility of a magnetic vortex in a flexible Fe81Ga19 nanoring

Abstract

Introducing a flexible substrate in functional devices often brings about stress-tunable properties. Ferromagnetic nanorings fabricated on flexible substrates hold promise for microwave applications based on a stretchable functional system. Here, through micromagnetic simulations, we report high-frequency dynamic properties of such FeGa nanorings each with a magnetic vortex, concentrating on the dynamic susceptibility and the spatial structure of relevant resonance modes in response to an induced tensile or compressive stress. It is seen that the fundamental resonance frequency varies significantly with the mechanical stress and ring width. Furthermore, spatial profiles of the resonance modes are found to evolve with the stress and ring width, resulting in a repeated fluctuation in dynamic susceptibility. Our findings provide guidance for the design of stress tunable microwave devices.