Nuclear orientation of 154EuFe, 166TmGd and 169YbFe and 169YbGd

Nuclear orientation measurements at low temperatures have been carried out on radioactive isotopes of 154Eu and 169Yb in Fe and of 166Tm and 169Yb in Gd. Gamma-rays from 169YbGd, obtained by the decay of implanted and melted sample of 169IuGd, were observed to have smaller anisotropies of opposite signs compared with those from 169YbFe. This may indicate that for Yb polarized in Gd electric quadrupole interaction is comparable with magnetic dipole one. Mixing ratios of the transitions in 154Gd, 166Er and 169Tm have been made for two levels in 166Er. Our analysis showed that the 3- to 3+ beta decay to the 1128 keV level in 154Gd has 65(20)% Δjβ=0. (orig.)