Temperature dependences of magnetoimpedance of nanocrystalline Fe-based ribbons.

The influence of a magnetic field or the mechanical stresses on the impedance of the Fe73.5Si16.5B6Nb3Cu1 and Fe73.5Si13.5B9Nb3Cu1 ribbons was investigated in the (297 divided by 433) K temperature range. It is shown that impedance changes, which are observed under the application of mechanical stresses and temperature, are conditioned by the structural features and magnetic properties of the alloys. The temperature increase leads to a decrease of the saturation magnetostriction constant, an increase of the anisotropy axis dispersion and a decrease of the anisotropy effective value. It was determined that the maximum sensitivity of impedance to the mechanical stresses reaches the value of about 2%/MPa for the Fe73.5Si16.5B6Nb3Cu1 and Fe73.5Si13.5B9Nb3Cu1 samples.