Stress-induced giant magneto-impedance effect of amorphous CoFeNiSiPB ribbon with magnetic field annealing

Abstract

The development of high-performance magnetic field-sensitive materials is in urgent need for magnetic sensors. In this paper, the effect of magnetic field annealing on the soft magnetic properties, thermal stability and stress-induced giant magneto-impedance (GMI) effect of Co69Fe5.5Ni1Si14.5-xPxB10 (x = 0, 0.5, 1, 1.5, 2) amorphous alloys were investigated in detail. Thermal analysis shows that replacing Si with a small amount of P can increase the thermal stability of the amorphous alloys. The permeability of the samples with magnetic field annealing is about 150% higher than that of the samples with stress-relieve annealing. The stress-induced GMI (GSI) results show that when the applied tensile stress is 0 MPa, 100 MPa, and 300 MPa, the maximum GMI ratio of the 1 at. % P-doping alloy with magnetic field annealing first increases from 76.6% to 102.8% and then decreases to 82%. Under the optimized measurement conditions, the magnetic field response sensitivity ξ of the Co69Fe5.5Ni1Si13.5P1B10 ribbon reached to 35.3%/Oe, the GSI ratio reached 34.3%, which has significant improvement compared to that of the stress-relieve annealing samples. Therefore, the magnetic field annealing technique greatly improved the GSI effect of the Co-based amorphous alloys, and the results obtained show a new way to develop high-performance GSI sensor materials and can be used in the construction of stress sensors.