MAGNETIZATION AND FE-57 HYPERFINE FIELDS IN Y2FE17Z3-DELTA(Z = H, C, OR N) INTERSTITIAL COMPOUNDS

Measured magnetization and Fe-57 hyperfine fields at T approximately 0 K for Y2Fe17 and Y2Fe17Z3-delta, with Z = H, C, or N and delta approximately 0.5, are analyzed to determine the influence of the interstitial atoms on the 3d magnetism. All are weak ferromagnets with a nearly-full 3d subband, although when Z = N, the magnetic moment of 38.1-mu(B) is very close to the fully saturated value of 39.4-mu(B). On a local scale, the order of hyperfine fields B(hf)4f(= 35 T) > B(hf)6g (= 33 T) > B(hf)12j (= 30 T) > B(hf)12k (= 28 T) is different from that of the local magnetic moments given by several recent band calculations for Y2Fe17, mu(4f) (= 2.5-mu(B)) > mu(12j) (= 2.2-mu(B)) > mu(12k) (= 2.0-mu(B)) > mu(6g) (= 1.9-mu(B)), reflecting a large 4s-transferred hyperfine field at 6g sites which have very short Fe-Fe distances. The volume of samples with Z = C and N are identical, and so the chemical effects of the interstitials can be distinguished; both the local magnetic moment and hyperfine fields are systematically smaller in the carbide than the nitride by 5% and 12%, respectively.