Magneto-impedance effect in amorphous ribbons for stress sensor application

The attractive magnetic properties of Go-rich amorphous ribbons in the high frequency range make these materials suitable for observing the magnetoimp edance (MI) effect. This phenomenon is related to the strong dependence of the impedance on the frequency of the driving current at frequencies higher than 100 kHz. In this work we discuss the possibility of using this effect In Co66.3Fe3.7Si12B18 amorphous ribbons, submitted to different annealing treatments for stress sensors. The application of tensile stresses changes the effective anisotropy field and influences the MI effect. High change ra tes of tensile stress can be measured from the variation of the effective a nisotropy field, up to about 200 MPa/Oe at 1 MHz for a stress relieved samp le. (C) 2000 Elsevier Science B.V. All rights reserved.