Assessing the relaxation mechanisms contributions on magnetoimpedance effect in YIG/W bilayers

Abstract

Damping parameter plays a key role in the magnetization dynamics of ferri/ferromagnetic materials with potential technological applications. Experimentally the damping parameter can be estimated from the linewidth of the ferromagnetic resonance experiment, which is altered by distinct mechanisms associated with extrinsic contributions, such as spin pumping and two-magnon scattering mechanisms. Here we perform a systematic investigation of the magnetization dynamics through magnetoimpedance effect in Y5Fe3O12(t)/W(100 nm) bilayers having t YIG between 25 and 125 nm. By modifying the YIG thickness, we explore the contributions of such extrinsic mechanisms to α eff . From the structural features, quasi-static magnetic properties, and ferromagnetic resonance results, we interpret our findings for the magnetization dynamics. Our results disclose that the bilayer structure allows us to explore the magnetoimpedance effect in a wide range of frequency and magnetic fields, providing insights on the effective damping parameter.