Giant magnetoimpedance effect in as quenched Fe_89-xZr₇B₄Cu_x(x=1.0-2.5) ribbons

The giant magnetoimpedance (GMI) effect in as-quenched Fe_89-xZr₇B₄Cu_x (x=1.0-2.5) ribbons is reported. The as-quenched Fe_89-xZr₇B₄Cu_x (x=1.0-2.5) ribbons were prepared by the vacuum melt-spun processes withthe quenching speed of 37m/s. The magnetoimpedance measurement were performed at room temperature, where the current flows through the length of the ribbons in the direction parallel to the dc fields. Results show that values Z (impedance), R (resistance) and X (reactance) forboth H=0 A/m and H=5 127 A/m increases with increasing ac frequency. This can be explained by the skin effect mechanism. The GMI effect almostcan not be found in the Cu content (mass fraction) range x ≤ 1.5%. With increasing Cu content x > 1.5%, the GMI effect become evident for as-quenched Fe_89-xZr₇B₄Cu_x (^x=1.0-2.5) ribbons. GMI ratio (Z(0)Z(H)/Z(0)) in as quenched Fe_86.5Zr₇B₄Cu_2.5 with melt-spun quenching speed of canreaches 33.69% at H=5 127 A/m. This indicated that good GMI properties can be also obtained in as-quenched FeZrBCu ribbons without annealing.