In a series of ${}_{}{}^{78}{}_{}{}^{}\mathrm{Kr}$ bombardments of ${}_{}{}^{92}{}_{}{}^{}\mathrm{Mo}$ the new isotopes ${}_{}{}^{166}{}_{}{}^{}\mathrm{Pt}$ and ${}_{}{}^{167}{}_{}{}^{}\mathrm{Pt}$ were identified via their $\alpha$-decay properties. The $\alpha$-decay energies and half-lives of these two nuclides are as follows. (1) ${}_{}{}^{166}{}_{}{}^{}\mathrm{Pt}$, $E_{\alpha }=7110\mathrm{}\left(15\right)\mathrm{}$ keV, $T_{\frac{1}{2}}=0.3\mathrm{}\left(1\right)\mathrm{}$ ms, and (2) ${}_{}{}^{167}{}_{}{}^{}\mathrm{Pt}$, $E_{\alpha }=6988\mathrm{}\left(10\right)\mathrm{}$ keV, $T_{\frac{1}{2}}=0.7\mathrm{}\left(2\right)\mathrm{}$ ms. Also, the half-life of ${}_{}{}^{168}{}_{}{}^{}\mathrm{Pt}$, which was previously unknown, was determined to be 2.0(4) ms. In a separate but concurrent experiment involving ${}_{}{}^{78}{}_{}{}^{}\mathrm{Kr}$ + ${}_{}{}^{96}{}_{}{}^{}\mathrm{Ru}$ reactions, ${}_{}{}^{170}{}_{}{}^{}\mathrm{Pt}$ was made and a half-life of 14.7(5) ms was measured for it; the one published value is $6_{-2\mathrm{}}^{+5\mathrm{}}$ ms. Results for ${}_{}{}^{162-164}{}_{}{}^{}\mathrm{Os}$ contained in the same data sets were also analyzed and by using mother-daughter correlations, the $\alpha$ branches of ${}_{}{}^{162,163,164}{}_{}{}^{}\mathrm{Os}$ were established to be near 100%.

• Received 11 March 1996

DOI:https://doi.org/10.1103/PhysRevC.54.R20