Magneto-inductive effect in tension-annealed amorphous wires and MI sensors

Small sized and sensitive MI elements are presented using cold drawn and then tension-annealed zero-magnetostrictive amorphous wires having a 50 μm diameter and a 2 mm length. An amplitude of an inductive voltage induced between both ends of the wire which is circumferentially magnetized with a wire AC current decreases about 80% against an external DC field of about 200 A/m, while the voltage amplitude increases from almost zero value for an external DC field when a rectifield or DC-biased AC field is applied to the wire. A new MI effect is also presented. An amplitude of a double frequency voltage induced between both ends of a folded amorphous wire due to magnetizing with a circumferential flux in an adjacent amorphous wire increases about ten times for a perpendicularly applied external DC field