MAGNETIC-PROPERTIES OF SM2FE17NY WITH AL SUBSTITUTED FOR FE

By means of X-ray diffraction analysis, it is shown for x < 0.4 that a ll the interstitial Sm-2(Fe1-xAlx)(17)N-y nitrides and the parent comp ounds crystallize with Th2Zn(17)-type structure. The lattice constants of the parent compounds increase linearly with Al concentration. The introduction of nitrogen atoms leads to a further increase in the latt ice constants, but the increase becomes smaller with increasing Al con centration; this can be related to the fact that the nitrogen content introduced into the parent compounds decreases nearly linearly with in creasing Al concentration. The dependence on composition of T-c of the parent compounds exhibits a maximum, whereas T-c of the nitrides decr eases monotonically with Al content from 750 K for x=0 to 313 K for x= 0.4. The introduction of nitrogen leads to enhancement of the average magnetic moment of Fe in Sm2Fe17, whereas the substitution of Al for F e leads to a decrease in the average magnetic moment of Fe in both the nitrides and the parent compounds. The anisotropy field B-a of nitrid es is almost independent of the Al concentration for x less than or eq ual to 0.3, then decreases very fast and becomes zero at about x = 0.4 .