STRUCTURE AND MAGNETISM OF MULTIPHASE SM0.080CO0.645FE0.276 POWDERS

A Sm-poor mixture of Fe-substituted Sm2Co17, having the nominal stoich iometry of Sm0.080Co0.645Fe0.276, was ball-milled to explore the possi bility of enhancing its remanence through direct microstructural refin ement. With milling, the Sm-2(Co0.7Fe0.3)(17) compound disassociates t o a body-centered-cubic supersaturated SmCoFe solid solution and a res idual SmCoFe amorphous phase. Correspondingly, the coercive field valu es first increase, peaking at 0.83 kOe after 180 min of milling, then decrease with continued milling to <0.1 kOe after 1200 min. The remane nce, as M-r/M-s, is measured to track closely the coercive field behav ior, experiencing modest increases to 0.26 after just 120 min of milli ng. Magnetization values are found to increase first with the dissocia tion of the 2:17 phase, and again with the ejection of Sm from the bcc component. (C) 1997 American Institute of Physics.