Behavior of the amorphous ferromagnetic ribbons in the very low fields

Abstract

The D.C. and A.C. magnetic properties and loss factors of five Co‐based amorphous ribbons with different compositions in the low magnetic fields were measured. The results show that there is a distinct turning field H_p for B(H), μ(H_m) and 2πtan δ/μ−B_m. The existence of H_p can be explained by means of the domain wall pinning effect in the low fields. The measured H_p corresponds to the minimum pinning field (∼10 mOe) in samples. It is suggested that the large gradient of intrinsic stresses in the ribbons is main cause of the low field pinning effect on domain walls; then we obtained a formula for H_p which was estimated to be 2–20 milli‐Oersteds.