2024/12/20 by Lorenzo Gnoatto, Gnoatto, Lorenzo, Thomas Molier +11
Materials Science · Physics and Astronomy · #Magnetic Properties of Alloys #Magnetic Properties and Applications #Magnetic properties of thin films
paper · pdf · doi:10.48550/arxiv.2412.15954
For magnonics and spintronics applications, the spin polarization (P) of a transport current and the magnetic damping (α) play a crucial role, e.g. for magnetization dynamics and magnetization switching applications. In particular, P in a glassy (amorphous) 3d transition ferromagnet such as CoFeB and α are both strongly affected by s-d scattering mechanisms. Hence, a correlation can be expected which is a priori difficult to predict. In this work, P and α are measured using current-induced Doppler shifts using propagating spin-wave spectroscopy and broadband ferromagnetic resonance techniques in blanket films and current-carrying Co\rm xFe_\rm 80-xB\rm 20 alloy microstrips. The measured P ranges from 0.18 ± 0.05 to 0.39 ± 0.05 and α ranges from (4.0± 0.2)⋅10-3 to (9.7± 0.6)⋅10-3. We find that for increasing P a systematic drop in α is observed, indicating an interplay between magnetic damping and the spin polarization of the transport current which suggests that interband scattering dominates in Co\rm xFe_\rm 80-xB\rm 20. Our results may guide future experiments, theory, and applications in advancing spintronics and metal magnonics.