Ferromagnetic resonance and magnetic anisotropy in YbMn6Sn6

The RMn6Sn6 (R = rare earth) family of kagome magnets exhibits a rich variety of magnetic states and unconventional electronic and magnetic properties. While the static magnetic properties of these materials have been extensively investigated, their magnetization dynamics remain less explored. Here, we investigate the magnetic anisotropy and dynamic magnetization of ferromagnetic YbMn6Sn6 using angle-dependent ferromagnetic resonance (FMR) spectroscopy and DC magnetization measurements. The angular dependence of FMR reveals the expected uniaxial anisotropy along the crystallographic c-axis, which is the global magnetically hard axis. In addition, we identify a pronounced twofold anisotropy within the ab-plane, which is independently confirmed by angle-dependent DC magnetization measurements. The observed uniaxial anisotropy in the ab-plane indicates a breaking of the expected sixfold rotational symmetry in the magnetic response that is attributed to growth induced anisotropy.