Tensile stress on giant stress-impedance effect of stress-current-annealed FeCoSiBCuNb amorphous ribbons

The stress-impedance (SI) effect of stress-current-annealed FeCoSiBCuNb amorphous thin ribbons was measured in the presence of longitudinal applied tensile stress. Stress value of sigma-(triangle Z/Z)max up to 245 MPa corresponding to peak GSI ratio (triangle Z/Z)max of 109% at 8 MHz was obtained, which may be the maximum stress value reported in our knowledge. Furthermore, controllable stress values corresponding to the peak GSI ratio were obtained, which is related to the pre-applied tensile stress while annealing. Through the observation of phase structure and magnetic domain structure, it is found that larger value of sigma-(triangle Z/Z)max corresponds to higher transverse component of the magnetic domain. The magnetic anisotropy field due to the residual stress and magnetoelastic energy of the annealed ribbon may be responsible for the variation of sigma-(triangle Z/Z)max. These results have reference value to the potential use of the stress-impedance effect in the design of stress sensors.