| 摘要 |
PURPOSE:To obtain an amorphous core for common mode choke, which is superior in frequency characteristics at the absolute value of permeability to a ferrite core for common mode choke and is superior in stability with time as well, by a method wherein an amorphous alloy having a specific composition is used as the material for the amorphous core for common mode choke. CONSTITUTION:An amorphous alloy having a composition, which is shown by a compositional formula =(Co1-a-bFeaMnb)100-x-y-zMxSiyBzX) (where the M is at least one kind of an element to be chosen out of the group of Ti, Zr, Hb, V, Nb, Ta, Cr, Mo, W, Ni and Cu) and has the relations of 0<=a<=0.10, 0.01<=b<=0.10, 1<=x<=8, 12<=y<=18 and 8<=z<=9.5 [the (x), the (y) and the (z) each shows an atomic ) is used as the material for the amorphous core for common mode choke. The Mn is essential in the composition and has an effect of making smaller the variation with time, and at the same time, has an effect of making larger the absolute value of permeability, but when the composition ratio (b) of the Mn is not more than 0.01, the above mentioned effects are not sufficient and when the composition ratio (b) exceeds 0.10, the core material becomes easy to embrittle and the manufacture of the amorphous alloy becomes difficult, so the composition ratio (b) is set at the ratio of 0.01<=b<=0.1. The composition ratio (a) of the Fe must be within an range of 0<=a<=0.1. When the (a) exceeds 0.1, the magnetic properties deteriorate as the magnetostriction increases. So it is not desirable to exceed 0.1. Accordingly the (a) shall be 0.1 or less. An amorphous alloy ribbon having a board thickness of 20mum or less among the amorphous alloy ribbons, which are the material for the amorphous core, is especially suitable for the use for the core for common mode choke.. |
