Nuclear Orientation of ${\mathrm{La}}^{140}$, ${\mathrm{Eu}}^{154}$, ${\mathrm{Gd}}^{159}$, ${\mathrm{Lu}}^{177}$, and ${\mathrm{Lu}}^{177 m}$ by Sternheimer Antishielding

Five rare-earth nuclei were oriented in neodymium ethyl sulfate and/or cerium magnesium nitrate lattices at very low temperatures, by utilizing the amplification of the crystal-field gradient (by a factor of ∼${10}^2$) provided by Sternheimer antishielding. The following quadrupole coupling constants $P$ were obtained in the ethylsulfate lattice (units of ${10}^{-5\mathrm{}}$ ${\mathrm{cm}}^{-1\mathrm{}}$): ${\mathrm{La}}^{140}$, -1.42(12); ${\mathrm{Eu}}^{154}$, -41.7(28); ${\mathrm{Gd}}^{159}$, -144(5); ${\mathrm{Lu}}^{177}$, -67(3); ${\mathrm{Lu}}^{177m}$, -13.0(12); and in the double nitrate lattice: ${\mathrm{La}}^{140}$, +1.10(16); ${\mathrm{Eu}}^{154}$, +1.5(1). The quadrupole moment for ${\mathrm{La}}^{140}$ was found to be +0.127 (13) b. The ratio of $\frac{Q\left({\mathrm{Lu}}^{177m}\right)}{Q\left({\mathrm{Lu}}^{177}\right)}$ is +2.33(25). The 815-keV $\gamma$ ray in ${\mathrm{Ce}}^{140}$ has $\delta \left(\frac{E2\mathrm{}}{M1\mathrm{}}\right)=-0.11\mathrm{}\mathrm{}\left(5\right)\mathrm{}$, if taken last in cascade. The signs and magnitudes of ($g_K-g_R$) for the $\frac{7}{2}-\left[514\right]\mathrm{}$ band and the $\frac{9}{2}+\left[624\right]\mathrm{}$ band in ${\mathrm{Hf}}^{177}$ were determined. Of special interest is the retention of nuclear orientation through the ∼1-sec isomeric states in ${\mathrm{Hf}}^{177}$.