Electric quadrupole moments of the K π = 8− and 23/2− isomeric states in 170, 171, 172Hf

Abstract

The spectroscopic quadrupole moments of the K π = 8 − isomers in 170 Hf and 172 Hf, Q s =4.91(17) b and 5.40(19) b, respectively and Q s =4.92(17) b for K π =23/2 − in 171 Hf have been measured using the time differential perturbed angular distribution technique. The nuclear reaction 160 Gd( 16 O, xnγ ) was used to excite the respective isomeric states and for the recoil implantation of Hf nuclei into the Hf foil. The quadrupole deformation for the 8 − isomer and the ground state has the same value. The deformation corresponding to 23/2 − isomeric state is observed to be reduced with respect to the ground state due to the i 13/2 neutron alignment. The results are in good agreement with the multi-quasiparticle calculations.