Mingzhong Wu’s group in our department measured for the first time high-temperature ferromagnetic resonance in media for heat-assisted magnetic recording. This work has been featured in a paper, with Daniel Richardson being the first author, that has been published in Physical Review Applied in November, 2018. https://journals.aps.org/prapplied/abstract/10.1103/PhysRevApplied.10.054046
Heat assisted magnetic recording (HAMR) makes use of a laser to heat the recording media to an elevated temperature, near the Curie temperature (Tc), to ease the switching of the magnetization. HAMR drives have been promised to be released to the market in the near future, but understanding of the damping in HAMR media at temperatures near Tc has not been realized yet. This work studies near-Tc damping properties of FePt-based media materials through high-temperature ferromagnetic resonances (FMR). The data suggest that at temperatures 10-45 K below Tc, two-magnon scattering and spin-flip magnon-electron scattering make comparable contributions to the FMR linewidth; with a decrease in temperature, the linewidth increases due to enhancement of the two-magnon scattering
