Nuclear magnetic resonance on oriented nuclei (NMR-ON) measurements were performed on the successive decays of ${}_{}{}^{89}{}_{}{}^{}\mathrm{-}_{}^{89}{}_{}{}^{}$${\mathrm{Y}}^{\mathit{m}}$ and ${}_{}{}^{191}{}_{}{}^{}\mathrm{-}_{}^{191}{}_{}{}^{}$${\mathrm{Ir}}^{\mathit{m}}$ in Fe. The NMR-ON spectra of ${}_{}{}^{89}{}_{}{}^{}\mathit{Fe}$ and ${}_{}{}^{191}{}_{}{}^{}\mathit{Fe}$ were obtained by detecting γ rays from the decay of the isomers, ${}_{}{}^{89}{}_{}{}^{}\mathrm{Y}_{}^{\mathrm{m}}{}_{}{}^{}$ and ${}_{}{}^{191}{}_{}{}^{}\mathrm{Ir}_{}^{\mathrm{m}}{}_{}{}^{}$, respectively. For ${}_{}{}^{89}{}_{}{}^{}\mathit{Fe}$, the anisotropy of the γ ray increased at the resonance. On the other hand, for ${}_{}{}^{191}{}_{}{}^{}\mathit{Fe}$ the anisotropy of the γ ray decreased at the resonance. These phenomena were explained using the spin inversion and spin noninversion processes including the lifetimes of the isomers and spin lattice relaxation times. NMR-ON measurements for such spin inversion and noninversion processes were reported. The resonance spectra were also observed by detecting β rays from ${}_{}{}^{89}{}_{}{}^{}\mathrm{Zr}$ and ${}_{}{}^{191}{}_{}{}^{}\mathrm{Os}$. In these experiments the magnetic moments of ${}_{}{}^{89}{}_{}{}^{}\mathrm{Zr}$ and ${}_{}{}^{191}{}_{}{}^{}\mathrm{Os}$ were determined to be -1.08 (2) ${\mathrm{\mu }}_{\mathrm{N}}$ and 0.962 (28) ${\mathrm{\mu }}_{\mathrm{N}}$, respectively. The signs of the magnetic moments of ${}_{}{}^{89}{}_{}{}^{}\mathrm{Y}_{}^{\mathrm{m}}{}_{}{}^{}$ and ${}_{}{}^{191}{}_{}{}^{}\mathrm{Ir}_{}^{\mathrm{m}}{}_{}{}^{}$ were also determined to be positive. © 1996 The American Physical Society.

• Received 29 May 1996

DOI:https://doi.org/10.1103/PhysRevC.54.1129