K. Majima et al., NEW MECHANICAL GRINDING PROCESS FOR ANISOTROPIC SM2FE17NX POWDER WITHA NANOCRYSTALLINE STRUCTURE, Journal of applied physics, 81(8), 1997, pp. 4536-4538
A new mechanical grinding (MG) process in NH3 and subsequent nitriding
in N-2 without a crystallization treatment was developed for synthesi
zing Sm2Fe17Nx powders. This process features a shorter MG time compar
ed to conventional MG to prevent amorpharization of the alloy structur
e and to avoid hydrogen in the ground powders which promotes a diffusi
on of nitrogen atoms into their particles. The Sm2Fe17Nx powder with x
=3.2 prepared by grinding for 10 h and subsequent nitriding at 723 K f
or 6 h showed magnetic anisotropy and its magnetic properties were I-r
=1.00 T, H-i(c)=0.61 MA m(-1), and (BH)(max)=129 kJ m(-3) (16.1 MGOe).
(C) 1997 American Institute of Physics.