Torsion-Dependent Circular Magnetization in Fe-Based Amorphous Wire

The circular permeability,  =  + j, of a Fe73.5Cu1Nb3Si13.5B9 annealed (500oC, 1 h) amorphous wire was obtained from the measurements of impedance, Z = R + jX = R + jL, as a function of circular magnetic AC field (H = 0.15 – 200A/m) and applied torsion ( = -7.5 – 11.5 rad/m). So the influence of  upon the circular magnetization has been studied. We found that the effects of applied torsion on the circular magnetization can be explained by considering the magneto-elastic interaction and a helical domain structure in the sample. The large change of  with  may be used as a torsion sensor.