Gyromagnetic ratios of 4+ and 6+ states in 156Gd and 158Gd

The following g-factors have been derived from time integral measurements of γ-γ angular correlations in the static magnetic hyperfine field of magnetized gadolinium metal probes: 156Gd: gξ(41+) = +0.310(1(9), gξ(61+) = +0.25(21), g(43+, 1511 keV) = +0.809(27), 158Gd: gξ(41+) = +0.409(15). The 5.35 d 156Tb sources were produced by the reaction 156Gd(d, 2n)156Tb in our cyclotron. A carrier-free 150 y 158Tb source was obtained from ISOLDE/CERN. In comparison with the precisely known gξ-factors of the 21+ states, gξ(21+,156Gd) = +0.386(4) and gξ(21+, 158Gd) = 0.381(4), we observe a large reduction for the 156Gd 41+ state whereas gξ increases slightly for 158Gd. The half-life of the 41+ state of 158Gd was remeasured as 158Gd: T1/2(41+) = 148(2) ps. A measurement of the rotation in the 43+ state of 156Gd in external magnetic fields of various strengths up to Bext = 9.5 T did not confirm the anomalous dependence of the magnetic hyperfine field in gadolinium metal on the external field, which has been reported by Persson et al. (orig.)