Tension annealing cold-drawn amorphous CoFeSiB wires

Amorphous magnetostrictive Co-Fe-Si-B wires exhibiting square and bistable hysteresis loops have been obtained by tension annealing treatments of the wires cold-drawn to lower than 0.05 mm in diameter from the as-quenched state (0.125 mm in diameter). Bistable switching characteristics were observed even in a 1-cm length of the annealed wire. The switching field is variable from 0.3 to 2.3 Oe with annealing condition, and fluctuation of the individual value is very small. It seems to be useful not only for a small pulse generator element, but also for classifying or identifying objects. Wires with asymmetric hysteresis loops have also been realized using this method.>