The impact of stress on magneto-impedance and achievement of high sensitivity in Co-based ribbons with three-peak behavior

In this paper, the Stress-Magneto-Impedance (S-MI) effect is investigated in Co-based ribbons by varying tensile stress and frequency. The MI changes are obtained as a function of applied stress and frequency ranged between 3.5 and 35 MPa and 1–12 MHz, respectively. Results are interpreted in terms of MI curve changes, modifying the applied mechanical stresses and measurement direction relative to the earth's magnetic field. A correlation between MI response, magnetic properties and tensile stress of the ribbons is illustrated, also the influences of processing and measurement parameters on the corresponding MI response were analyzed. A three-peak behavior is observed, indicating significant sensitivity which can be controlled by the earth's magnetic field to reform the measurement system. Vibrating sample magnetometer analysis results illustrate the magnetic behavior of the ribbon samples for longitudinal and transverse directions of magnetic field and out of plane. Due to the different responses for surface normal vector directions, this work provides useful insights into the fabrication of highly sensitive sensors.