高周波用Co基アモルフアス超薄帯磁心の磁気特性

抄録

Magnetic Properties of Ultrathin Co-Based Amorphous Ribbon Cores Masaaki Yagi, Member (Miyagi National Colledge of Technology), Takao Sawa, Nonmember (Toshiba, New Materials Engineering Laboratory), Jiro Yamasaki, Member (Kyushu Institute of Technology) Ultrathin[((Fe0.05Co0.95)0.95Cr0.05)75(Si0.5B0.5) 25, ((Fe0.05Co0.95)0.94Cr0.06)76(Si0.5B0.5)24] amorphous ribbons were fabricated by a single roller technique in vacuum. Extremely low core loss and high initial permeability were attained in the range of 100 kHz-10 MHz for the cores made of 4-5μm thick ribbons. For 4.7μm thick ribbons, the core loss at 1MHz was 0.86 J/m³(=860 mW/cc)for Bm=0.1T. This value was about 30-40% of those of Mn-Zn high-frequency ferrites and 5μm Supermalloy tape wound cores. In addition, the initial permeability of this core measured at 1 and 10MHz were about 13, 000 and 1, 200 for Hm=2mOe, respectively.
Furthermore, the effect of transverse magnetic field annealing on the magnetic properties was also studied. The domain patterns of some ultrathin ribbons were observed by the Kerr effect and their relation to the soft magnetic properties was discussed.