An ion-exchange process was developed for the separation of spectrographically pure praseodymium salts in kilogram amounts from commercially available concentrates. The application of either 0.5% or 0.1% citrate solutions as eluting agents was show to result in excellent separations of praseodymium from samarium, neodymium, and lanthanum when the mixed rare earths were eluted from Amberlite IR-...

Spectrographic methods applicable to the determination of major rare earth constituents in complex mixtures are described. The specific examples discussed are the determination of yttrium and gadolinium in the concentration range of 10 to 100 per cent. The procedures involve the high current DC arc excitation of rare earth oxide sample-ceric oxide-graphite mixtures. Selected lines of cerium are...

This paper reviews our recent experimental work on erbium incorporated into gallium arsenide during MBE growth. The electrical behaviour of the erbium is considered in relation to its interaction with intentionally added dopants (silicon, selenium and berylium) and the effect of the erbium on the deep state population is discussed. At higher concentrations the morphology of phase separation is ...

While the seismic quality factor and phase lag are defined solely by the bulk properties of the mantle, their tidal counterparts are determined by both the bulk properties and the size effect (self-gravitation of a body as a whole). For a qualitative estimate, we model the body with a homogeneous sphere, and express the tidal phase lag through the lag in a sample of material. Although simplisti...

A new non-fluorinated malonamide-based ionic liquid extractant was synthesized and investigated for the extraction behavior of europium(III) and other trivalent rare-earth ions from nitric acid medium. The extractant was the functionalized ionic liquid trihexyl(tetradecyl)phosphonium N,N,N',N'-tetra(2-ethylhexyl)malonate, [P66614][MA], and it was used in combination with the non-fluorinated ion...

Self-assembled atomic chains can be triggered at stepped Si(111) surfaces by adding sub-monolayer amounts of metals, such as gold, silver, platinum, alkali metals, alkaline earths, and rare earths. A common feature of all these structures is the honeycomb chain, a graphitic strip of Si atoms at the step edge that is lattice matched in the direction parallel to the edge but completely mismatched...

X-ray absorption and magnetization experiments are used to describe the oxidation states of the rare earth ions R=Ce, PI and Tb in the double layer high-Tc superconducting series RBa2Cu307 and Pb2Sr2R1-,CaXCu3O8. We obtained the same oxidation states for the rare earths in these two classes of compounds, namely, R=Ce tetravalent and R=Pr and Tb trivalent.