Title :
Induced anisotropy in nanocrystalline FeCuNbSiB
Author :
Emura, M. ; Severino, A.M. ; Santos, A.D. ; Missell, F.P.
Author_Institution :
Inst. de Fisica, Sao Paulo Univ., Brazil
fDate :
11/1/1994 12:00:00 AM
Abstract :
The kinetics of induced anisotropy Kind was studied in nanocrystalline Fe73.5Cu1Nb3Si13.5 B9, as well as in the amorphous precursor and in amorphous Fe78B13Si9. The nanocrystalline alloy was produced from the precursor by annealing at 813 K for 1 h and possessed an average FeSi grain size of 13 nm, as determined from X-ray diffraction. Annealing in a 0.2 T field at 723-773 K, above Tc of the amorphous phase, resulted in low values of Kind. The data were compared to the micromagnetic theory of Kronmuller to determine activation energy spectra. Kind for the nanocrystalline alloy is well described by this theory, however, with an activation energy spectrum that is much narrower than for the amorphous alloys. The limiting value of the anisotropy is K∞ ≈13 J/m3 consistent with that expected for the anisotropy in Fe-20at%.Si with the DO3 structure
Keywords :
X-ray diffraction; amorphous magnetic materials; boron alloys; copper alloys; ferromagnetic materials; grain size; induced anisotropy (magnetic); iron alloys; magnetic anisotropy; magnetic annealing; nanostructured materials; niobium alloys; silicon alloys; 723 to 773 K; DO3 structure; Fe73.5Cu1Nb3Si13.5B 9; Fe78B13Si9; FeCuNbSiB; X-ray diffraction; activation energy spectra; amorphous Fe78B13Si9; amorphous precursor; annealing; average FeSi grain size; induced anisotropy; kinetics; micromagnetic theory; nanocrystalline FeCuNbSiB; nanocrystalline alloy; Amorphous magnetic materials; Amorphous materials; Anisotropic magnetoresistance; Annealing; Grain size; Kinetic theory; Magnetic anisotropy; Magnetostriction; Perpendicular magnetic anisotropy; Saturation magnetization;
Journal_Title :
Magnetics, IEEE Transactions on
