The magnetic hyperfine splitting frequencies ${\nu }_M=\frac{g{\mu }_N{B}_{\mathrm{HF}}}{h}$ of ${}_{}{}^{105}{}_{}{}^{}\mathrm{Rh} (j^{\pi }=\frac{7}{2^{+}};T_{\frac{1}{2}}=35.4\mathrm{} h)$ as dilute impurities in Fe and Ni have been measured with nuclear magnetic resonance on oriented nuclei as ${\nu }_M\left({}_{}{}^{105}{}_{}{}^{}\mathrm{Rh}Ni\right)=218.06\mathrm{}\left(5\right)\mathrm{}$ MHz and ${\nu }_M\left({}_{}{}^{105}{}_{}{}^{}\mathrm{Rh}Fe\right)=539.62\mathrm{}\left(3\right)\mathrm{}$ MHz. With the hyperfine field $B_{\mathrm{HF}}\left({}_{}{}^{105}{}_{}{}^{}\mathrm{Rh}Fe\right)=-556.6\mathrm{}\left(1.2\right)\mathrm{}$ kG the $g$ factor of the ${}_{}{}^{105}{}_{}{}^{}\mathrm{Rh}$ ground state is derived as $\mathrm{}\left|g\right|=1.272\mathrm{}\left(2\right)\mathrm{}$. In combination with earlier nuclear orientation measurements $J^{\pi }={\frac{7}{2}}^{\mathrm{}(+)\mathrm{}}$ can be uniquely assigned. The $g$ factor fits well into the systematics of $\pi g_{\frac{9}{2}} g$ factors in this mass region and confirms the interpretation of this state as ${{\left(\pi g_{\frac{9}{2}}\right)}_{{\frac{7}{2}}^{+}}}^3$ shell model configuration. The hyperfine field of ${}_{}{}^{105}{}_{}{}^{}\mathrm{Rh}$Ni is deduced as - 224.9(5) kG for $T=0\mathrm{}$ K. Hyperfine anomalies, the abnormal resonance shift with $B_0$ and the overall systematics of $\pi g_{\frac{9}{2}}g$ factors are discussed.

RADIOACTIVITY ${}_{}{}^{105}{}_{}{}^{}\mathrm{Rh}$ from ${}_{}{}^{104}{}_{}{}^{}\mathrm{Ru}(n,\gamma ){}_{}{}^{105}{}_{}{}^{}\mathrm{Ru}\to {}_{}{}^{105}{}_{}{}^{}\mathrm{Rh}$; NMR on oriented nuclei; deduced $j$, $\mu$. Hyperfine fields, hyperfine anomaly. Knight shift.

• Received 19 December 1980

DOI:https://doi.org/10.1103/PhysRevC.23.2683