Spin Dynamics in Ferromagnetic Resonance for Nano-Sized Magnetic Dot Arrays: Metrology and Insight Into Magnetization Dynamics

The ferromagnetic resonance response (FMR) in the variously sized magnetic dot arrays was measured by using network-analyzer ferromagnetic resonance technique. We first demonstrated that the magnetization excitation related to the susceptibility χ_zx by the coplanar wave-guide (CPW). In this χ_zx, the edge mode excitation modified the FMR response appreciably and found that the damping constant is strongly affected by the size of the nano-magnet. In larger nano-magnets, two edge modes were observed. We showed that this edge mode can be exploited as a means to separately characterize the magnetization state of the nano-magnet as well as the size variation. In addition, the simulation results are also presented here to account for the experimental observations.