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 Ir¹⁹¹ and Ir¹⁹³ have nuclear spins 3/2, and the ratio of their magnetic moments is μ¹⁹³μ¹⁹¹=1.04±0.04, with μ¹⁹³=+0.17±0.03 nm. Their quadrupole moments are given by Q¹⁹³=(+1.0±0.5)×10^-24 cm² and Q¹⁹¹Q¹⁹³=1.2±0.4. Lines due to the transition d⁷s²-d⁷sp were observed to have an isotope displacement effect of the order of 0.063-0.071 cm^-1. (II) Os¹⁸⁹ has a nuclear spin 3/2, a nuclear magnetic moment +0.70 ±{}0.09 nm, and a quadrupole moment (+2.0±{}0.8) ×{} 10^-24 cm².