Rare earth-iron-nitrogen system permanent magnet and process for producing the same

A process for producing a permanent magnet comprising a rare earth, iron and nitrogen, comprising:

• compression molding, into a powder compact having an apparent density accounting for 40 to 90% of the true density, a powder of an interstitially nitrogenated T--R--N compound having a Th.sub.2 Zn.sub.17 crystal structure and comprising a composition expressed by a compositional formula T.sub.100-x-y R.sub.x N.sub.y, wherein T represents Fe or Fe containing 20% or less of at least one selected from the group consisting of Co and Cr as a partial substituent thereof;
• R represents at least one selected from the group consisting of rare earth elements inclusive of Y, provided that Sm accounts for 50 atm. % or more;
• and x and y each represent percents by atomic with x being in the range of from 9 to 12 and y being in the range of from 10 to 16;
• and
• charging said powder compact into a capsule and applying shock compression at a pressure as reduced to an equivalent drive force in an iron capsule of from 10 GPa to 25 GPa, thereby obtaining a solidified bulk magnet having an apparent density accounting for 90% or higher of the true density.