Bistable magnetization reversal in 50 µm diameter annealed cold-drawn amorphous wires

Amorphous magnetostrictive 50 μm diameter Fe77.5Si7.5B15wires exhibiting square and bistable hysteresis loops have been obtained by field-tension annealing and flash annealing treatments of cold-drawn as-quenched wires. Highest switching field, 1.3 Oe, and domain drive field, 0.5 Oe, for annealing temperature 330 C , time 30 min, axial tension 150 Kg/mm2and axial field 200 Oe are an order of magnitude improvement over the as-quenched (AQ) state. Corresponding induced peak voltage is 0.5 mV/turn with exciting sinusoidal field 2 Oe and 60 Hz. Shorter pulse generation elements (≈ 2 cm) than for AQ wires (≈ 6 cm) were realized with 0.5 mV/turn peak voltage. Maximum squareness ratio is close to unity, twice that of AQ (125 μm) wires.