Static electric quadrupole moments in the ground state and K=41- bands in 168Er

The time differential perturbed angular correlation (TDPAC) technique has been used to study the nuclear quadrupole interactions of the first excited state of ground state rotational band (2+, 80 keV, T1/2=1.88 ns) and the band head of the K=41- band (4-, 1094 keV, T1/2=120 ns) in the 168Er nucleus of a polycrystalline Er host. At room temperature we obtained the electric quadrupole interaction frequencies ω0(K=0)=457(15) Mrad/s and ω0(K=4)=69(2) Mrad/s, respectively, for the 2+ and 4- isomeric states of 168Er. The ratio of the spectroscopic quadrupole moments, i. e. Qs (K=4)/Qs(K=0)=0.69(3), is independent of any model approximation and the electric field gradient at 168Er in the host metal. (orig.)