Fe-57 hyperfine field anisotropy in ferrites and its relation to the non-uniformity of the ionic surrounding

The hyperfine field anisotropy tensors, obtained from analysis of Fe-57 NMR spectra for iron sites in various magnetic oxides (barium hexaferrite, lit hium spinel, magnetite and yttrium-iron garnet) were used to investigate th e relation between the hf anisotropy and surrounding ionic arrangement. Whi le a reasonable correlation has been found when the distribution of the nea rest cations was considered, no correlation was obtained between the hyperf ine field anisotropy and the positions of the nearest oxygen anions.