INFLUENCE OF NITROGEN-CONTENT ON COERCIVITY IN REMANENCE-ENHANCED MECHANICALLY ALLOYED SM-FE-N

In nanostructured Sm2Fe17Nx+alpha-Fe two-phase permanent magnets, exch ange interactions between hard and soft magnetic phases result in rema nence enhancement. With a starting composition of Sm7Fe93, mechanical alloying, annealing at 625 degrees C for 10 min and subsequent nitridi ng at 330 degrees C for 45 h results in hard magnetic powder with nano crystallites of Sm2Fe17N3 and alpha-Fe some 20 nm in size. There is a coercivity of mu(0)H(c) = 0.4 T and a remanence J(r) = 1.2 T, after sa turating in a field of 7.5 T. The deduced value of the remanence depen ds strongly on the choice of demagnetizing factor.