Circular magnetization and energy loss in Fe-based soft magnetic wires

•Similar circular-field-dependent circular permeability, μ=μ′−jμ″, have been observed in two Fe-based wires with different domain structure.•Different mechanisms of circular magnetization in two samples have been discussed by analyzing the energy loss.•Domain structure, circular magnetization processes and energy loss have been correlated by studying the influences of axially applied field.

The circular permeability, μ=μ′−jμ″, of two Fe-based soft magnetic wires with longitudinal (S1) and transverse (S2) domain structure, respectively, were determined from the measurements of impedance, Z=R+jωL, as functions of frequency (f=102–104 Hz), AC current amplitude (I=0.1–100 mA) and DC axially applied field (H=0–5.4 kA/m). So the influences of f and H upon the circular magnetization have been studied experimentally. Although the two samples exhibit similar changes of μ=μ′−jμ″ with the circular-field, Hφ, different technique magnetization processes, referred to different domain structures of samples, has been discussed by analyzing the energy loss according to a current theoretical model. Consequently, we have concluded that the circular magnetization is dominated by domain magnetization rotations and domain wall displacements in samples S1 and S2, respectively.