EVIDENCE FOR MAGNETIC-INTERACTIONS BETWEEN DISTANT CATIONS IN YITTRIUM IRON-GARNET

The NMR spectrum of Fe-57 nuclei in high purity Y3Fe5O12 garnet (YIG) is reported. The satellite structure of this spectrum is caused by an antisite defect (Y3+ ion replacing an Fe3+ ion). Resolved satellite lines, which correspond to the Fe3+ ion in six different cation coordination spheres around the defect, are observed. In particular, satellite lines arising from the Fe3+ ions' distance of which from the defect is as large as 1.07 nm (11th coordination sphere) are identified unambiguously. The results yield information on the range of magnetic interactions in YIG.