Anisotropy of hyperfine field in diamagnetically substituted YIG

The results of the nuclear magnetic resonance of 57Fe in Al-, Ga- and In-substituted Y3Fe5O12 garnets are reported. When diamagnetic Ga3+ or Al3+ ions are substituted for tetrahedral Fe3+ ions, four satellite lines in the NMR spectrum of octahedral Fe3+ ions appear. The substitution of In3+ ions for octahedral Fe3+ ions leads to three satellite lines in the spectrum of tetrahedral Fe3+ ions. The hyperfine fields of these satellites are explained using the independent bond model for the hyperfine interaction. Suprisingly large change of the anisotropic part of the hyperfine field relative to the isotropic one was found.