Torsion measurements using inverse Wiedemann effect in glass covered amorphous wires

This article presents results concerning inverse Wiedemann effect (IWE) dep endence on the torsion applied along the Fe77.5Si7.5B15 glass covered amorp hous wires tested before and after glass removal. In the absence of torsion during measurements, the IWE voltage is zero for amorphous wires tested in the as-cast state. In the same condition of measurements a small spontaneo us IWE voltage appears for wires after glass removal annealed without torsi on, and the voltage reaches its maximum value for torsion annealed wires bo th before and after glass removal. Increasing the torsion's value during me asurements, for as-cast wires and wires annealed without torsion, the value of the induced voltage increases until it reaches a maximum while for tors ion annealed wires a small increase is observed followed by a strong decrea se down to that torsion value at which the thermal treatment was performed. In the case of torsion annealed wires a good linearity of the torsion resp onse was obtained for a given range of torsions which depends on the sample 's state (before and after glass removal). The obtained results suggest the possibility to use IWE in Fe77.5Si7.5B15 glass covered amorphous wires in torque sensors. (C) 1999 American Institute of Physics. [S0021-8979(99)3260 8-6].