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.