2009/05/31 by J.-M. L. Beaujour, J-M. Beaujour, D. Ravelosona +6 · 149 citations
Engineering · Materials Science · Physics and Astronomy · #Anisotropy #Atomic physics #Condensed matter physics #Ferromagnetic resonance #Ferromagnetism #Film plane #Laser #Laser linewidth #Magnetic Properties and Applications #Magnetic anisotropy #Magnetic field #Magnetic properties of thin films #Magnetization #Magneto-Optical Properties and Applications #Materials science #Optics #Permalloy #Physics #Resonance (particle physics) #cond-mat.mes-hall #cond-mat.mtrl-sci
paper · pdf · doi:10.1103/physrevb.80.180415
published in Physical Review B 80(18) (American Physical Society)
arxiv created 2009/06/15 · openalex publication_date 2009/11/17 · openalex created_date 2025/10/10 · openalex updated_date 2026/08/05
Transition-metal ferromagnetic films with perpendicular magnetic anisotropy (PMA) have ferromagnetic resonance (FMR) linewidths that are one order of magnitude larger than soft magnetic materials, such as pure iron (Fe) and Permalloy (NiFe) thin films. A broadband FMR setup has been used to investigate the origin of the enhanced linewidth in a material in which the PMA could be systematically reduced by irradiation with Helium ions: Ni\ensuremath|Co multilayers. The FMR linewidth depends linearly on frequency for perpendicular applied fields and increases significantly when the magnetization is rotated into the film plane. Irradiation of the film with Helium ions decreases the PMA and the distribution of PMA parameters, leading to a large reduction in the FMR linewidth for in-plane magnetization. These results suggest that fluctuations in PMA lead to a large two magnon scattering contribution to the linewidth for in-plane magnetization and establish that the Gilbert damping is enhanced in such materials (\ensuremathα\ensuremath≈0.04, compared to \ensuremathα\ensuremath≈0.002 for pure Fe).