Title :
FMR spectra of oriented γ-Fe2O3, Co-γ-Fe2O3, CrO2 and MP tapes
Author :
Yu, Y. ; Harrell, J.W.
Author_Institution :
Dept. of Phys. & Astron., Alabama Univ., Tuscaloosa, AL, USA
fDate :
11/1/1994 12:00:00 AM
Abstract :
Ferromagnetic resonance spectra have been measured at 34.5 GHz on oriented γ-Fe2O3, Co-γ-Fe2O 3, CrO2 and MP tapes. Particle orientation distribution functions were determined by measuring the angular dependence of remanence. The distribution functions were used to calculate FMR spectra using the Landau-Lifshitz equation and the method of Netzelmann. The anisotropy energy, packing fraction and damping constant were adjusted in order to fit the data. The values of the damping constants obtained from the fits ranged from a low of 0.051 for CrO2 to a high of 0.92 for MP. These values, including previously measured damping constants for Ba-ferrite, correlate well with the switching speed measurements of Doyle and co-workers, which show CrO2 to be the slowest and MP the fastest
Keywords :
chromium compounds; cobalt; ferromagnetic resonance; iron compounds; magnetic anisotropy; magnetic particles; magnetic switching; magnetic tapes; remanence; γ-Fe2O3; 34.5 GHz; Co-γ-Fe2O3; CrO2; FMR spectra; Fe2O3; Fe2O3:Co; Landau-Lifshitz equation; MP; anisotropy energy; damping constant; ferromagnetic resonance spectra; metal particle; oriented tapes; packing fraction; particle orientation distribution functions; remanence; switching speed; Damping; Distribution functions; Extraterrestrial measurements; Magnetic anisotropy; Magnetic field measurement; Magnetic resonance; Particle measurements; Perpendicular magnetic anisotropy; Remanence; Velocity measurement;
Journal_Title :
Magnetics, IEEE Transactions on
