Large Barkhausen effect and Matteucci effect in cold-drawn and torsion annealed amorphous magnetostrictive wires

Amorphous magnetostrictive wires fabricated by super-rapid quenching in water exhibit a remarkably stable Barkhausen effect and Matteucci effect in the as-prepared state. The Matteucci effect in as-prepared wire is under 1 mV. When the wire is drawn or made shorter than 70 mm, the Barkhausen effect vanishes. In this work, the amorphous magnetostrictive wire was cold drawn and then annealed under torsional stress; the wires obtained had a large Matteucci effect, as well as a large Barkhausen effect even when as short as 25 mm. These wires were used as devices for pulse generation. Their magnetic properties are studied