Magnetic Properties of Amorphous Metal Wires

The properties of Fe-Si-B system and Co-Fe-Si-B system wires were studied. B-H loops of the wires varied greatly with applied magnetic field and sample length. At lengths greater than 5 cm peculiarly large Barkhausen effects appeared. It was discovered that driving an ac current through the wires induced a reverse Matteucci effect. The phases reverse with direction in which the wire is twisted, and this seems to be due to the fact that the directions of the domain walls change with the twisting angle which occurs due to the circumference field induced by the current flowing within the wire.