Title :
High electrical resistivity and permeability of soft magnetic granular alloys
Author :
Fujimori, Hiroyasu ; Mitani, Seiji ; Ikeda, Toru ; Ohnuma, Shigehiro
Author_Institution :
Inst. for Mater. Res., Tohoku Univ., Sendai, Japan
fDate :
11/1/1994 12:00:00 AM
Abstract :
The electrical resistivity and magnetic properties were investigated on sputtered CoFeB-O and CoAl-O granular alloy thin films, which are considered to be new-type of magnetic thin film useful in the very high frequency region. A tunnel-hopping conductivity described by exp(αT-1/2) was observed in films with higher O content. The coefficient α, proportional to the root of tunnel-activation energy, was smaller than that of similar granular systems composed of a mixture of metallic and non-metallic particles. The frequency dependence of the permeabilities in these films was remarkably flat up to high frequencies (~50 MHz), although the loss terms were slightly larger than those calculated by the Landau-Lifshitz equation using the observed high resistivities
Keywords :
aluminium alloys; boron alloys; cobalt alloys; electrical resistivity; ferromagnetic materials; granular materials; hopping conduction; iron alloys; magnetic permeability; magnetic thin films; oxygen; soft magnetic materials; sputtered coatings; 50 MHz; CoAl-O; CoAl-O granular alloy thin films; CoFeB-O; Landau-Lifshitz equation; electrical resistivity; frequency dependence; loss terms; magnetic properties; magnetic thin film; permeability; soft magnetic granular alloys; sputtered CoFeB-O; tunnel-activation energy; tunnel-hopping conductivity; very high frequency region; Conductive films; Conductivity; Electric resistance; Equations; Frequency dependence; Magnetic films; Magnetic properties; Permeability; Soft magnetic materials; Sputtering;
Journal_Title :
Magnetics, IEEE Transactions on
