Stoner-Wohlfarth Model for Nanocrystalline Anisotropic Sm<sub>2</sub>Co<sub>17</sub> Magnets

Abstract

The Stoner-Wohlfarth model can be used for predicting hysteresis curves of either isotropic or anisotropic nanocrystalline Sm 2 Co 17 type magnets. For isotropic magnets, with Mr/Ms=0.5, the Stoner-Wohlfarth model predicts coercive force of 48% of the anisotropy field. Here, Mr is remanence and Ms is magnetization of saturation. Two texture distributions were compared: Pearson VII and cos n . The calculations indicate that increasing the alignment degree of the grains, the coercivity increases. However, this increase of the coercive force is small. It is found that a very well aligned magnet, with Mr/Ms ratio of 0.96, presents coercivity only ~20% higher than that of the isotropic magnet.