Abstract
The spectroscopic quadrupole moments of the K-pi = 8(-) isomers in Hf-170 and Hf-172, Q(s)=4.91(17) b and 5.40(19) b, respectively and Q(s)=4.92(17) b for K-pi=23/2(-) in Hf-171 have been measured using the time differential perturbed angular distribution technique. The nuclear reaction Gd-160(O-16, xn gamma) 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.