Near-Tc Ferromagnetic Resonance and Damping in FePt-Based Heat-Assisted Magnetic Recording Media

Heat-assisted magnetic recording (HAMR) employs a laser to heat the recording medium nearly to its Curie temperature ${T}_{C}$, to ease magnetization switching. HAMR hard drives have been promised for the near future, yet an understanding of magnetic damping in HAMR media at such temperatures has not been realized. This study of the near-${T}_{C}$ damping properties of FePt thin films on MgO through ferromagnetic resonance (FMR) suggests that just below ${T}_{C}$, two-magnon scattering and spin-flip magnon-electron scattering make comparable contributions to the FMR linewidth, while at lower temperatures two-magnon scattering dominates.