Nuclear g factors and structure of high-spin isomers in 190,192,194Pt and 196,198Hg

The integral perturbed angular distribution (IPAD) method in an external magnetic field has been used to measure the g factors of isomers in the 190,192,194Pt and 196,198Hg nuclei, populated in the (α,2n)-reaction. The results are as follows: 190Pt, g(12+)=−0.17(12), g(10−)=−0.0016(36), g(7−)=+0.62(9); 192Pt, g(12+)=−0.18(9), g(10−)=−0.0012(10), g(7−)=0.48(12); 194Pt, g(12+,new assignment)=−0.17(7), g(7−)=+0.26(8); 196Hg, , g(7−)=−0.030(17); 198Hg, , g(7−)=−0.033(14). The intrinsic structure of the isomers is discussed. The 12+ states have the rotational-aligned structure. The missing rotation-aligned state is suggested to be isomeric in 194Pt (instead of the 10+ state) and to which the g=−0.17(6) value has to be attributed. From the g factors of the 10− states in 190Pt and 192Pt, which have the configuration ν9/2−[505]⊗ν11/2+[615], the anomalous gl-factor for neutrons has been derived as δgl=−0.028(6). The trend from negative g factors of the 7− states in the 196,198Hg nuclei to positive values for the corresponding states in the 190,192,194Pt nuclei indicates a change in the intrinsic structure of the lowest negative-parity bands, from mainly in Hg to mainly in Pt.