Title :
High-resistive (CoFeB)-(SiO2) soft magnetic amorphous film for micro-cores in a few MHz range
Author :
Munakata, Makoto ; Yagi, Masaaki ; Shimada, Yutaka
Author_Institution :
Energy Electron. Lab., Kumamoto Inst. of Technol., Japan
fDate :
9/1/1999 12:00:00 AM
Abstract :
Highly resistive (CoFeB)-(SiO2) amorphous films were deposited on glass substrates and polyimide sheets by synchronous dual-rf magnetron sputtering. SiO2 volume fraction dependence of magnetic properties and resistivity was investigated. The as-deposited films for SiO2 volume fraction υ=20 vol.% had low coercivities of Hc=0.2-0.3 Oe, together with high resistivities of 1500-2200 μ Ω cm. The film exhibited an anisotropy field 40 Oe, a relative permeability of 200 and a saturation magnetization of 7.3 kG. The core loss of the films was 1-1.5 J/m3 at 1 MHz for maximum flux density Bm=0.1 T. The loss was found to be as low as those of Co-based ultra-thin ribbons. The films are useful as thin film cores in the micromagnetic elements which work in the MHz range
Keywords :
amorphous magnetic materials; boron alloys; cobalt alloys; coercive force; electrical resistivity; ferromagnetic materials; iron alloys; magnetic anisotropy; magnetic cores; magnetic leakage; magnetic permeability; magnetic thin films; magnetisation; metallic glasses; silicon compounds; soft magnetic materials; sputter deposition; 0.1 T; 1 MHz; 1500 to 2200 muohmcm; CoFeB; SiO2; SiO2 volume fraction dependence; anisotropy field; as-deposited films; core loss; glass substrates; high resistivities; high-resistive (CoFeB)-(SiO2) soft magnetic amorphous film; highly resistive (CoFeB)-(SiO2) amorphous films; low coercivities; magnetic properties; maximum flux density; micro-cores; polyimide sheets; relative permeability; resistivity; saturation magnetization; synchronous dual-rf magnetron sputtering; Amorphous magnetic materials; Amorphous materials; Conductivity; Glass; Magnetic anisotropy; Magnetic films; Perpendicular magnetic anisotropy; Polyimides; Saturation magnetization; Substrates;
Journal_Title :
Magnetics, IEEE Transactions on
