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

Abstract

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 <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">zx</sub> by the coplanar wave-guide (CPW). In this χ <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">zx</sub> , 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.