Engineering of magnetic properties and GMI effect in Co-rich amorphous microwires

Abstract

We studied the effect of annealing conditions on magnetic properties of amorphous CoFeNi-based glass-coated microwires. We showed that annealing can be very effective for manipulation of the magnetic properties of amorphous ferromagnetic glass-coated microwires. Low coercivity and high Gaint magnetoimpedance (GMI) effect have been observed in as-prepared Co-rich microwires. After annealing of Co-rich we can observe transformation of linear hysteresis loops to rectangular and coexistence of fast magnetization switching and GMI effect in the same sample. We demonstrated that the coercivity of microwires can be tailored by annealing in the range from 4 to 200 A/m. We found that the annealing considerably affects the magnetostriction coefficient and observed correlation between the magnetic hardening of studied microwires and the magnetostriction sign change.