Magnetic coupling of the composite mixtures Sm2Co17/Sm2Fe17N3 and Sm2Co17/Fe

Abstract

Mixing magnetically oriented 100 μm particles of coercive Sm2Co17 with 2–10 μm particles of Sm2Fe17N3 produces an enhanced hysteresis loop compared with the weighted averaged loops of the individual materials. The critical parameters involved are the sizes of the particles and the ratio of the two phases present. In 50:50 Sm2Co17/Sm2Fe17N3, two phase mixtures, an increase in the coercivity from 0.9 to 1.0 T and a small increase in remanent magnetization is observed. Similar increases also appear in 50:50 mixtures of Sm2Co17 and α–Fe. The enhanced hysteresis loops are explained by the anisotropic nature of the dipolar interaction which causes the small particles to cluster near the magnetic axes of the larger one.