Torsion measurements using inverse Wiedemann effect in glass covered amorphous wires

Abstract

This article presents results concerning inverse Wiedemann effect (IWE) dependence on the torsion applied along the Fe77.5Si7.5B15 glass covered amorphous 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 spontaneous IWE voltage appears for wires after glass removal annealed without torsion, and the voltage reaches its maximum value for torsion annealed wires both before and after glass removal. Increasing the torsion’s value during measurements, for as-cast wires and wires annealed without torsion, the value of the induced voltage increases until it reaches a maximum while for torsion annealed wires a small increase is observed followed by a strong decrease 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 response 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.