High Spin-Wave Propagation Length Consistent with Low Damping in a Metallic Ferromagnet

Abstract

We report ultra-low intrinsic magnetic damping in Co${}_{\text{25}}$Fe${}_{\text{75}}$ heterostructures, reaching the low $10^{-4}$ regime at room temperature. By using a broadband ferromagnetic resonance technique, we extracted the dynamic magnetic properties of several Co${}_{\text{25}}$Fe${}_{\text{75}}$-based heterostructures with varying ferromagnetic layer thickness. By estimating the eddy current contribution to damping, measuring radiative damping and spin pumping effects, we found the intrinsic damping of a 26\,nm thick sample to be $$α_{\mathrm{0}} \lesssim 3.18\times10^{-4}$.Furthermore,usingBrillouinlightscatteringmicroscopywemeasuredspin-wavepropagationlengthsofupto$(21\pm1)\,\mathrm{μm}$ina26nmthickCo$_{\text{25}}$Fe$_{\text{75}}$ heterostructure at room temperature, which is in excellent agreement with the measured damping.

Updated Version