Damping in Iron Thin Films: Recent Experimental Insights*

Confirming the origins of Gilbert damping by experiment has remained a challenge for many decades. This is the case even for some of the simplest and most technologically relevant ferromagnetic metals, such as pure Fe. In this presentation, we will discuss our findings that provide crucial – and counterintuitive – insights into the mechanisms of damping in Fe thin films. We will first present evidence for intrinsic “conductivity-like” Gilbert damping, where cleaner epitaxial films can exhibit higher damping at low temperatures [1]. We will also show that room-temperature intrinsic Gilbert damping in polycrystalline Fe is remarkably insensitive to the film microstructure [2]. These findings constitute a path forward in understanding the fundamentals of damping in ferromagnetic metals for practical device applications.

[1] B. Khodadadi et al. Phys. Rev. Lett. 124, 157201 (2020)

[2] S. Wu et al. arXiv:2109.03684