Evaluation of anisotropy field in amorphous Fe71+xNb7B22−x alloys by GMI measurement

Abstract We have measured the variation of magnetoimpedance (MI) ratio on Fe 71+ x Nb 7 B 22− x ( x =0, 2, 6, 8) amorphous ribbons for the evaluation of anisotropy field H k . MI at a frequency of 10 MHz is related to the transverse permeability from rotational magnetization. MI varies sensitively with the various Fe-contents, reflecting the magnetic softness. The field interval of the MI peaks corresponds to the anisotropy field ( H k ) and the estimated H k decreases with the Fe-contents.