Thickness And Angular Dependent Ferromagnetic Resonance Of Ultra-Low Damping Co25fe75 Epitaxial Films

Metallic ferromagnets with ultra-low damping are highly desirable for charge-based spintronic applications. Here, we systematically investigate the magnetic dynamics of Co25Fe75 epitaxial films with a Gilbert damping constant as low as 7.1 x 10 x 4. The in-plane angular dependence of ferro-magnetic resonance (FMR) was measured on various thicknesses of Co25Fe75 films grown on MgO and MgAl2O4, from which the mechanisms for FMR linewidth broadening can be distinguished and quantified. The thickness dependencies of the magnetic anisotropy and inhomogeneous broadening of the linewidth are good indicators of crystal quality and magnetic uniformity. Additionally, it is shown that anisotropic two-magnon scattering is induced by defects at the surfaces. Published by AIP Publishing.