An amorphous ribbon of Fes4.5Zr2Nb4B 8.5Cu1 has been prepared by single-roll melt spinning in
an Ar atmosphere. The crystallization process studied by differential scanning calorimetry (DSC) is in
agreement with that in the Kissinger model and the Johnson-Mehl-Avrami (JMA) model. The
magnetoimpedance ratio (MIR) of the ribbon has been measured to investigate the influence of the structural
transformation in the crystallization process and the changes of the soft magnetic properties after thermal
treatment. The magnetoimpedance (MI) of these samples has been studied in the frequency range from 1
MHz to 5 MHz by varying a dc magnetic field within 300 Oe. A maximum MI ratio of up to 85 % has been
observed for ribbons annealed at 530 ?C for 40 min around a frequency of 1 MHz. The incremental
permeability ratio (PR) shows drastic changes in soft magnetic properties as a function of the annealing
temperature.
