Research and Development of Interstitial Compounds

The interstitial rare earth-iron compounds exhibiting a variety of magnetocrystalline anisotropies, large saturation magnetization, and high Curie temperature provide the basis for high-performance magnetic materials. In this paper, a manufacturing process for mass production of anisotropic magnetic powders has been successfully developed for Nd(Fe, M)(12)N (NdFeN) and Sm2Fe17N3 (SmFeN) compounds with uniaxial anisotropy. The magnetic powders of Nd(Fe, M)(12)N have maximum energy products [(BH)(max)] around 22 MGOe. The calendar magnets of NdFeN show the rolling anisotropy and have a (BH)(max) up to 5.9 MGOe with excellent mechanical properties and good anticorrosion ability. The (BH)(max) of SmFeN magnetic powders is up to 41 MGOe, which is favorable for fabricating high-performance injection magnets and extrusion magnets. On the other hand, it was found that cone or planar anisotropic R2Fe17Nx (R = Ce, Pr, Nd) and paraffin composites can improve the Snoek limit and exhibit a high microwave reflection loss of up to -35 dB at about 14 GHz, presenting an advantage for application as a high-performance thin-layer microwave absorber. These results open up broad prospects for technological applications using interstitial modified compounds.SCI(E)ARTICLE115