Stress-controlled dynamic susceptibility in FeGa stripes

Knowledge of the dynamic magnetic susceptibility of patterned films is of great importance for exploring future data-storage applications and microwave devices. Since ferromagnetic resonance frequency is a function of the geometric parameters of a certain magnetic system, in this work, we investigate by micromagnetic simulations a set of stripe-patterned FeGa films, which have an identical thickness of 10 nm but a varying width in the range of 30–80 nm and a varying length in the range of 200–1000 nm. Fast-Fourier transform analysis of the simulation results for ferromagnetic resonance calculation identifies two distinct resonance peaks, which are assigned to a “bulk” mode and an “edge” mode. The presence of stress-induced anisotropy significantly affects both the two resonant modes. The occupation area of the spreading magnetization near the stripe ends is controllable by a tensile or compressive stress applied along the strip width. Consequently, the dynamic susceptibility of FeGa can be adjusted by an applied stress.