Mechanism of magnetization reversal in Nd/sub 15.1/Fe/sub 76.9/B/sub 8/ permanent magnets

Major and minor hysteresis loop measurements have been performed on Nd/sub 15.1/Fe/sub 76.9/B/sub 8/ sintered magnet. The coercivity as a function of the maximum magnetizing field has been determined. This dependence appeared to be typical of nucleation hardened materials. The domain structure behaviour during the magnetization reversal has been observed on the surface parallel to the alignment direction of the sample. Domain structure photographs have been correlated with suitable points on both virgin and demagnetization curves, respectively. It was stated from this observation that the demagnetization process occurs by the nucleation of reversed domains at the grain boundaries.<
>