NMR Study of Bismuth-Substituted Yttrium Iron Garnets

Bismuth-substituted yttrium iron garnets have been studied with NMR measurement. The NMR signals of 209 Bi nuclei were observed around 40 MHz corresponding to the internal field of 60 kOe. This value is about one order higher than the value expected from dipole field of ferric ions. This suggests the possibility of partial spin polarization of bismuth ion through the electron transfer from Bi 3+ to Fe 3+ . This may cause the growth-induced anisotropy cooperating with preferential site ordering of bismuth ion.