The Size Effects on High Frequency Magnetic Properties of Amorphous Wires

The frequency dependence of the permeability, jU^, in amorphous Co-Fe- Si-B wires was investigated as a function of the wire diameter, annealing temperature, tensile stress and drawing parameters. Results show that the level of ¿i and the critical frequency for holding ¿i constant depend mainly on the wire diameter, suggesting that eddy currents affect ¿i at high frequencies. It was also found that two-stage annealing, in which drawing followed by annealing was performed twice, results in an improved frequency characteristic of ¿i