LARGE BARKHAUSEN DISCONTINUITIES OF DIE-DRAWN FE-SI-B AMORPHOUS WIRE

Magnetic properties and domain structure were investigated for die-dra wn and subsequently annealed Fe-Si-B amorphous wires. It was found tha t the die-drawn wire has bamboo domain similar to that of the Co based wire with negative magnetostriction and looses the re-entrant flux re versal characteristic. It was also found that the wire recovers the re -entrant characteristic after annealing. The tension-annealed wire has clear shell and core domain structure and exhibits the re entrant cha racteristic with enhanced remanence. The surface bamboo domain layer a s thin as 5 mu m was connected to the core domain by magnetization tha t changes direction continuously between two domains without domain wa ll. From the temperature dependence of a threshold field for the disco ntinuous flux jump, it is inferred that the re entrant characteristic is caused by the depinning of the reverse domain existing near the wir e end due to demagnetizing effect.