Determination of magnetization rotation and domain wall motion components in reversible complex susceptibility spectra of Co-based amorphous ribbons with various annealing times

The complex susceptibility spectra for the Co₆₆Fe₄Ni₁B₁₄Si₁₅ ribbons annealed at 380°C under external magnetic field of 3 Oe with various annealing times were measured in reversible magnetization range. The susceptibility spectra originating from both relaxation processes of reversible domain wall motion and magnetization rotation are separated from the complex susceptibility spectra measured for the samples. The variation of static susceptibilities and relaxation frequencies of domain wall motion and magnetization rotation with annealing time indicate that the alignment of domains to external field direction onset at the annealing time is about 5 min and is accomplished at about 20 min. For short annealing time <5 min, magnetic softening is the main effect on magnetization processes.