Large Barkhausen Discontinuities of Die-Drawn Fe-Si-B Amorphous Wire

摘要

Magnetic properties and domain structure were investigated for die-drawn and subsequently annealed Fe-Si-B amorphous wires. It was found that the die-drawn wire has bamboo domain similar to that of the Co based wire with negative magnetostriction and looses the re-entrant flux reversal 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 characteristic with enhanced remanence. The surface bamboo domain layer as thin as 5 mu m was connected to the core domain by magnetization that changes direction continuously between two domains without domain wall. From the temperature dependence of a threshold field for the discontinuous flux jump, it is inferred that the re entrant characteristic is caused by the depinning of the reverse domain existing near the wire end due to demagnetizing effect.