THE INFLUENCE OF INTERSTITIAL HYDROGEN, CARBON AND NITROGEN-ATOMS ON THE YTTRIUM HYPERFINE FIELD IN Y2FE17 AND Y2CO17

The nuclear magnetic resonance spin echo spectra of Y2Fe17Ax (A = N, C, H) and Y2Co17Cx are presented. Going from hydrogen through nitrogen to carbon, an increasing influence of the interstitial atoms on the yttrium hyperfine field is found. A remarkable increase of the iron hyperfine field caused by nitrogen is observed. The above effects have strongly local character and are attributed to the influence of nitrogen, carbon and hydrogen atoms on the local electronic structure at rare earth and transition metal sites in the structure.