Ferromagnetic resonance of particulate magnetic recording tapes

TLDR: In this article, the room temperature ferromagnetic resonance (FMR) spectra of γ•Fe2O3, CrO2, and barium ferrite particulate magnetic recording tapes have been measured at microwave frequencies of 9.35 and 35 GHz for various orientations of the static and high frequency magnetic fields with respect to the tape.

Abstract: The room‐temperature ferromagnetic resonance (FMR) spectra of γ‐Fe2O3, CrO2, and barium ferrite particulate magnetic recording tapes have been measured at microwave frequencies of 9.35 and 35 GHz for various orientations of the static and high‐frequency magnetic fields with respect to the tape. For CrO2 tapes, the influence of the width of the angular distribution of the particle orientations on the FMR spectra has been studied from the nearly isotropic case up to the highly oriented case. Hysteretic behavior for a CrO2 tape as well as the effect of tape calendering for a γ‐Fe2O3 tape has been observed by FMR. Experimental results are found to be in reasonable agreement with results of theoretical calculations based on a model of an ellipsoidal single‐domain particle with both shape and magnetocrystalline anisotropy. Magnetostatic interaction inside the magnetic film has been introduced by expressing the total magnetostatic energy as a combination of a part dependent on particle shape and a part dependent...