G. Bordin et al., Bending effects and temperature dependence of magnetic properties in a Fe-rich amorphous wire, J MAGN MAGN, 233(3), 2001, pp. 187-194
Amorphous wires with composition Fe77.5Si7.5B15 exhibit a very peculiar mag
netization process characterized by a single and quite large Barkhausen jum
p. This gives rise to a squared hysteresis loop at a critical magnetic fiel
d. The bistable behaviour, widely studied in wires with typical length of 1
0 cm and diameter of 125 mum, appears above a length of about 7 cm in strai
ght wires and disappears for curvature radius within the range 2-12 cm in b
ent wires. In this work it is shown that bistability occurs in bent wires,
whatever their curvature is, provided the wires are long enough. To this pu
rpose spiral-shaped samples with several turns are considered. However, whe
n the wire length is not a integer number of turns the magnetization revers
es through many large Barkhausen jumps. In this condition, varying the meas
uring temperature can activate the energy barriers for the jumps. (C) 2001
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