Nitrogenated 1:12 compounds prepared by mechanical alloying

Nd(FeM)/sub 12/ compounds, with M=Mo, Ti, and V, prepared by mechanical alloying were nitrogenated using the gas phase interstitial modification process. The Nd(FeM)/sub 12/ structure has been found to be stable after nitrogenation at around 650 degrees C, but with increased lattice parameters. The change in unit cell volume, delta V/V, is larger in mechanically alloyed powders than in as-cast alloy powders. The change of Curie temperature upon nitrogenation is almost the same delta T/sub c//T/sub c/ approximately=30%, for the three compounds studied. The mechanically alloyed powders and metal-bonded magnets with the ThMn/sub 12/ crystal structure show interesting hard magnetic properties with a coercivity H/sub c/=7-10 kOe. The average grain size of the mechanically alloyed powders with the highest coercivity was shown about 4000 AA.<
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