The size effects on high frequency magnetic properties of amorphous wires.

The frequency dependence of permeability μi in amorphous Co-Fe-Si-B wires was investigated as a function of wire diameter, annealing temperature, tensile stress and drawing parameters. Results show that the level of μi and the critical frequency to maintain μi constant were mainly dependent on wire diameter, suggesting the eddy current effect on μi at high frequencies. Furthermore, the two stage annealing in which drawing and annealing were alternatively repeated twice was found to result in improving the frequency characteristics of μi.