MAGNETOINDUCTIVE EFFECT (MI EFFECT) IN AMORPHOUS WIRES

Circumferential magnetic properties of amorphous magnetic wires (a-wire, for short) having three kinds of compositions (FeSiB, CoSiB and FeCoSiB) and diameters (120-mu-m, 50-mu-m) are investigated applying an AC current using a BH hysteresis tracer. Magnitude of the induced voltage between both ends of the a-wire is decided by a differential permeability regarding circumferential flux change which is considered to occur principally in the outer shell of a-wires. Sensitive magneto-inductive effect (MI-effect, for short) is newly found in a wires, in which the value of inductance of a zero-magnetostrictive a-wire of 5mm length changes up to about 75% for an external field of 0.8 kA/m (10 Oe). This MI-effect is shown to be applicable to small magnetic heads and a cordless data tablet.