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

Volume

30

Issue

6

fYear

1994

fDate

11/1/1994 12:00:00 AM

Firstpage

4779

Lastpage

4781

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;

fLanguage

English

Journal_Title

Magnetics, IEEE Transactions on

Publisher

ieee

ISSN

0018-9464

Type

jour

DOI

10.1109/20.334219

Filename

334219