Canted standing spin-wave modes of Permalloy thin films observed by Ferromagnetic Resonance

DOI: 10.1088/1367-2630/abdd6b

Authors: Maciej Dabrowski (University of Exeter) , Robert J. Hicken (University of Exeter) , Andreas Frisk (Diamond Light Source) , David G. Newman (University of Exeter) , Alpha T N'Diaye (Advanced Light Source) , Christoph Klewe (Advanced Light Source) , Padraic Shafer (Advanced Light Source) , Gerrit Van Der Laan (Diamond Light Source) , Thorsten Hesjedal (University of Oxford) , Graham Bowden (University of Southampton)
Co-authored by industrial partner: No

Type: Journal Paper
Journal: New Journal Of Physics

State: Published (Approved)
Published: January 2021

Abstract: Ferromagnetic resonance (FMR) and x-ray detected FMR (XFMR) results for Permalloy (Py) and [Co/Pt]10/Py films, with and without thin Pt spacers between the [Co/Pt]10 and Py layers, are presented and discussed. The first layer [Co/Pt]10 was chosen due its characteristic perpendicular anisotropy, with the potential to pin neighboring Py spins. However, in practice, the FMR results were found to be dominated by the 50-nm-thick Py films, especially when the thickness of the Pt spacer exceeds 1.5 nm. Nonetheless, out-of-plane FMR measurements reveal interesting behavior. In particular, the uniform k=0 mode is extremely sensitive to the alignment of the magnetic field normal to the film. Misalignment by just 3° shifts the cusp, at Bappz ~ μ0M in the plot of resonance frequency against applied field, upwards to ~ 6 GHz. In addition, out-of-plane VNA-FMR maps reveal the presence of additional modes. For example, a perpendicular standing spin-wave (PSSW)-state, above the cusp at Bappz ≥ μ0M, is clearly identified. However, as the magnetic field is reduced below the cusp, the PSSW state morphs, continuously, through a series of canted spin-wave states (CSSW) into a horizontal standing spin-wave (HSSW) state, increasing in frequency to ~ 9.5 GHz. Finally, the PSSW, CSSW and HSSW states, are accurately interpreted, using a multi-layer model of the Py film.

Diamond Keywords: Ferromagnetism

Subject Areas: Materials, Physics

Facility: Beamline 4.0.2 at Advanced Light Source

Added On: 28/01/2021 08:38

Documents:
Dabrowski+et+al_2021_New_J._Phys._10.1088_1367-2630_abdd6b.pdf

Discipline Tags:

Surfaces Quantum Materials Hard condensed matter - electronic properties Physics Magnetism Materials Science interfaces and thin films

Technical Tags: