(CoFeB)-(SiO_2)系アモルファス高電気抵抗膜の磁気特性  [in Japanese] Magnetic Properties of Highly Electrical Resistive (CoFeB)-(SiO_2) Amorphous Films  [in Japanese]

(CoFeB)-(SiO_2) amorphous magnetic films for magnetic cores of micro-magnetic power devices were deposited on glass substrates by a synchronous dual-rf magnetron sputtering method. The relation between the magnteic properties and resistivities of the films and core losses was investigated. Highly electrically resistive soft magnetic Co_<66.6>Fe_<7.4>B_<26>-SiO_2 films with low core losses in the high-frequency range were obtained by reducing the hysteresis losses. The films exhibited an anisotropy field of 40 Oe, a permeability of 200 and a saturation magnetization of 7.3 kG. The core loss of the films for a coercivity of 0.20 Oe and a resisitivity of 2200μΩcm was less than 1 J/M^3 at 1 MHz, B_m=0.1T, as good as that of Co-based ultra-thin soft magnetic amorphous ribbons.