Article surveillance magnetic marker having an hysteresis loop with large barkhausen discontinuities at a low field threshold level

摘要

A harmonic-type EAS marker includes a wire segment formed of cobalt alloy. To form the wire segment, the cobalt alloy is cast as an amorphous wire, die-drawn to a smaller diameter, and then annealed with application of longitudinal tension. The annealed wire is cut to produce wire segments which have a magnetic hysteresis loop with a large Barkhausen discontinuity at a lower threshold level than has previously been achieved.