Nuclear magnetic resonance on oriented rare-earth nuclei in rare-earth hosts: Application to 160Tb.
We summarize the application of nuclear magnetic resonance of oriented nuclei to rare-earth impurities implanted in ferromagnetic crystals of heavy rare-earth hosts. The experimental aspects are treated in some detail; we present results obtained on $^{160}\mathrm{Tb}$$\mathrm{Tb}$, and give a formal description of the experiments. A discussion of extension to other, similar systems with applications in nuclear, solid-state, and low-temperature physics is given.
Nuclear orientation study of160Tb impurity in yttrium single crystal
The low temperature nuclear orientation of160Tb impurity in yttrium single crystal has been studied in the temperature range 5–60 mK and in the external magnetic field up to 9 T applied along a- or c-crystal axes. The experimental results are interpreted as a consequence of the interaction of Tb3+ ion with crystal field produced by the yttrium neighbours. A possible influence of technology used is also discussed.
Nuclear quadrupole alignment ofLum176andLu177in a lutetium single crystal at low temperatures and systematics of electric field gradients in pure hexagonal transition metals
The quadrupole frequencies for $^{176}\mathrm{Lu}^{m}$ and $^{177}\mathrm{Lu}$ nuclei in a Lu single crystal have been determined by nuclear orientation at temperatures down to 6 mK as -128(16) MHz and +294(37) MHz, respectively. From the observed $\ensuremath{\gamma}$ anisotropies several $\ensuremath{\gamma}$-ray multipole mixing ratios could be derived. With the known ground-state quadrupole moment of $Q=3.39(2)$ b for $^{177}\mathrm{Lu}$ the electric field gradient of $\mathrm{Lu}\mathrm{Lu}$ is found to be +3.6(5) \ifmmode\times\else\texttimes\fi{} ${10}^{17}$ V/${\mathrm{cm}}^{2}$. This value does not fit into the frame of Raghavan's universal correlation. Taking into account recent data on other systems, a new classification of electric field gradients in hexagonal metals is proposed: The electronic contribution to the total electric field gradient is proportional to the ionic part, the proportionality constant being positive for all group-$\mathrm{III}b$ and -$\mathrm{IV}b$ hexagonal metals and negative for all group-$\mathrm{II}b$, -$\mathrm{VII}b$, and -$\mathrm{VIII}b$ metals.