Inverse Wiedemann effect in Fe–Al alloys for torque sensing applications

Magnetoelastic effects have proved to be powerful for sensing applications. In this work, the inverse Wiedemann effect (IWE) of melt spun ribbons of Fe–Al with giant magnetostriction is studied. The basic characterization of the IWE response to torsion with no amplification yields a remarkable sensitivity, as high as 68 mV/(rad m−1), with a relative standard deviation of repeatability of only 0.05%, and a linearity error of 0.4% FSR in a range of ±2 rad m−1. Although the largest magnetostriction has been reported to correspond to 19% Al, Fe83Al17 has a higher Wiedemann effect. The results confirm that quenched Fe–Al ribbons are promising candidates for IWE-based sensing applications.

► An automatic measurement set-up of the inverse Wiedemann effect is presented.
► IWE has been measured in giant magnetostrictive Fe–Al ribbons.
► A high output voltage and linear response have been obtained around null twist angle.
► Fe–Al ribbons have proved to be suitable for torsion sensing applications.