Hyperfine Structure in the Spectra of Iridium and Osmium

The hyperfine structure in the spectra of Ir I and Os I was studied and the following results were obtained. (I) Both ${\mathrm{Ir}}^{191}$ and ${\mathrm{Ir}}^{193}$ have nuclear spins $\frac{3}{2}$, and the ratio of their magnetic moments is $\frac{{\mu }^{193}}{{\mu }^{191}}=1.04\mathrm{}\pm 0.04$, with ${\mu }^{193}=+0.17\mathrm{}\pm 0.03$ nm. Their quadrupole moments are given by $Q^{193}=(+1.0\mathrm{}\pm 0.5)\times {10}^{-24\mathrm{}}$ ${\mathrm{cm}}^2$ and $\frac{Q^{191}}{Q^{193}}=1.2\mathrm{}\pm 0.4$. Lines due to the transition $d^7{s}^2-d^7\mathrm{sp}$ were observed to have an isotope displacement effect of the order of 0.063-0.071 ${\mathrm{cm}}^{-1\mathrm{}}$. (II) ${\mathrm{Os}}^{189}$ has a nuclear spin $\frac{3}{2}$, a nuclear magnetic moment +0.70 ±0.09 nm, and a quadrupole moment (+2.0±0.8) × ${10}^{-24\mathrm{}}$ ${\mathrm{cm}}^2$.