DEFECTS IN FERRITES STUDIED BY FE-57 NMR

Presence of defects in ferrites gives rise to a modification of the hy perfine field on nuclei of those iron ions, which are situated in the neighborhood of the defect. If the concentration of defects is small, satellite structure of the NMR spectra of Fe-57 nuclei is observed. An alysis of this satellite structure provides valuable information. In p articular concentration of the defect, its distribution over various s ublattices, magnetic moment and the valency may be obtained. In the pr esent paper we describe how the analysis of the satellite structure is performed, summarize the requirements on the NMR experiment and illus trate the method using several examples of defects in the yttrium iron garnet.