Domain wall pinning, bulging, and displacement in circumferential domains in CoFeBSi amorphous wires

A detailed study of the complex inductance response of as-cast CoFeBSi wires as a function of frequency (100 Hz-13 MHz range) and circular field amplitude [0.1-17 A/m room mean square (rms) on the surface of the wire] in the giant magnetoimpedance arrangement is presented. The analysis of experimental results show evidence of magnetization processes associated with circumferential domain walls, such as domain wall pinning, bulging, and displacement. The unpinning field was measured as 0.2 A/m (rms) at 5 kHz. It is shown that the analysis of spectroscopic plots of real and imaginary inductance leads to characterization of the magnetization process involved. (C) 2000 American Institute of Physics. [S0021-8979(00)20708-1].