Mechanism of re-entrant flux reversal in Fe-Si-B amorphous wires

The mechanism of re-entrant flux reversal in Fe-Si-B amorphous wires was investigated by domain observation and reverse domain detection focusing on the magnetic properties near the wire ends. It was found that the wire consists of shell and core domains and that the core region has the residual reversing domain due to demagnetizing field near wire ends in a remanent state. The residual domain was stabilized by forming a flux closure structure through the shell domain, which increases the threshold field for domain growth to a value much larger than the wall coercivity and results in predominantly re-entrant flux reversal.