Torsion dependence of giant magnetoimpedance in amorphous wires

The effect of stresses is known to modify the magnetic properties in magnetostrictive amorphous wires. A comparative study of the giant magnetoimpedance (GMI) for amorphous wires with compositions Fe77.5Si7.5B15, Co72.5Si12.5B15 and Co68.15Fe4.35Si12.55B15 and positive (30×10−6), negative (−2×10−6) and vanishing (0.1×10−6) magnetostriction have been studied. The influence of torsional stress on hysteresis loops and GMI is also reported. Modifications of GMI response are ascribed to the magnetoelastic anisotropy induced by torsion.