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The 57 Fe NMR spectra of pure yttrium iron garnet, measured at 4.2 K, exhibit a well-resolved satellite structure caused by antisite defects (yttrium ions replacing iron on a sites). The analysis of the a site spectra, obtained in a magnetic field of 0.75 T applied in several directions in the (1 1 0) plane, yielded the values of the isotropic and anisotropic terms of the hyperfine field for four resolved satellite sets.

Low-temperature nuclear orientation has been applied to the study of the nuclear spin-lattice relaxation (SLR) of60Co in the Co phase of a single-crystalline [Co(21 A) /Fe(24 A)]25 multilayer. The Co layers previously were shown to follow the bcc structure of Fe. The hyperfine field (Bhf) distribution was studied by NMR on59Co in the same sample. We applied the thermal cycling (TC) method at temperatures around 9 mK in the external magnetic field (Bext) range 0.05–1 T to determine the SLR, which was found for Co in bcc Co to be about seven times faster than the SLR of Co in Fe. Moreover, the (Bext) dependence of the SLR as observed for impurities in Fe and Co in fcc Co was not found.