NMR of57Fe in erbium-yttrium iron garnets

NMR of 57Fe was studied by the two pulse spin echo method in systems Er(x)Y(3−x)Fe5012. For small (x 2.7) concentrations of Er the spectra of 57Fe exhibit resolved satellite lines. The splitting between the satellite and the parent line reflects the change of the dipolar field on the Fe nuclei (diamagnetic yttrium is replaced by magnetic erbium ion) and the change which the substitution causes in the electronic structure of the ferric ion. Relative importance of these effects is discussed.