Effective Grinding Procedure for Sm2Fe17Nx Powder with High-Performance Permanent Magnetic Characteristics

Abstract
Finely and uniformly ground powder samples (mean particle size 2Fe17N x (x= approx. 3.0) which were obtained by ball milling in hexane solution containing a surface-active agent for 1-3 days, provided high remanence (B r) and coercivity ( i H c) values: B r=1.2-1.3 T and i H c=0.9-1.1 MA· m-1 (11-14 kOe), although their mean particle size (<3 µ m) was still larger than that of the calculated one for the single magnetic domain (∼0.3 µ m). These excellent magnetic characteristics were attributed to size uniformity, surface smoothness, and less strain induced in the finely ground powder particles.