Magnetic Dipole Moments of First2+States in Even Osmium Nuclei Recoil-Implanted in Nickel

The ion-implantation-perturbed-angular-correlation technique has been used to measure the $g$ factors of the first ${2}^{+}$ excited states of four even osmium nuclei in a ferromagnetic nickel host. The observed angular precessions were: $\ensuremath{\omega}\ensuremath{\tau}(^{192}\mathrm{Os})=0.22\ifmmode\pm\else\textpm\fi{}0.01$, $\ensuremath{\omega}\ensuremath{\tau}(^{190}\mathrm{Os})=0.277\ifmmode\pm\else\textpm\fi{}0.009$, $\ensuremath{\omega}\ensuremath{\tau}(^{188}\mathrm{Os})=0.39\ifmmode\pm\else\textpm\fi{}0.03$, and $\ensuremath{\omega}\ensuremath{\tau}(^{186}\mathrm{Os})=0.38\ifmmode\pm\else\textpm\fi{}0.08$. The angular precession result for $^{192}\mathrm{Os}$ is in excellent agreement with the results of perturbed-angular-correlation measurements in nickel using radioactive sources. It was found that the internal field seen by the osmium nuclei implanted in nickel is in good agreement with the value obtained by room temperature NMR techniques. The available direct lifetime measurements for $^{186,188}\mathrm{Os}$ and lifetimes extracted from $B(E2)$ values for $^{190,192}\mathrm{Os}$ are used to obtain the gyromagnetic ratios: $g(^{192}\mathrm{Os})=0.39\ifmmode\pm\else\textpm\fi{}0.03$, $g(^{190}\mathrm{Os})=0.39\ifmmode\pm\else\textpm\fi{}0.03$, $g(^{188}\mathrm{Os})=0.29\ifmmode\pm\else\textpm\fi{}0.03$, and $g(^{186}\mathrm{Os})=0.24\ifmmode\pm\else\textpm\fi{}0.05$.