Transient hyperfine field measurements of gyromagnetic ratios in Os and Pt nuclei

Precessions were measured of the $2_1^{+}$ states in ${}_{}{}^{192}{}_{}{}^{}\mathrm{Os}$ and ${}_{}{}^{198}{}_{}{}^{}\mathrm{Pt}$ in the enhanced transient field in thin cobalt foils and comparison made with similar recent studies of ${}_{}{}^{188}{}_{}{}^{}\mathrm{Os}$ and ${}_{}{}^{194}{}_{}{}^{}\mathrm{Pt}$ ions in Fe foils. It is concluded that (i) the transient field acting on Pt in Fe is singularly anomalous, and (ii) recent contention by Levy et al. that the $g$ factors of even Pt $2_1^{+}$ states may be substantially lower than reported earlier cannot be sustained.