Lanthanides, nuclear properties

The various materials used, along with the lanthanide additive and the applications, are given in the form of tables based on the properties such as mechanical, chemical, electrical and magnetic, emission of radiation and interaction with electromagnetic radiation. The applications based on the mechanical and nuclear properties are given in Table 12.21. 

The very slight differences that do exist among these elements are due to small changes in size brought about by increase of nuclear charge. The separation of the lanthanide elements from each other is based upon clever exploitation of these slight differences in properties. Table 23-1 shows a comparison of some of the properties of the various lanthanide elements. As can be seen, +3 is the common oxidation number and is most characteristic of the chemistry of these elements. Another thing to note is the steady decrease in... 

The last of the lanthanides, this metal is also the hardest and the densest of them. It is a component of cerium mischmetal. Lutetium has some applications in optoelectronics. Shows great similarities to ytterbium. Its discoverer, Georges Urbain, carried out 15 000 fractional crystallizations to isolate pure lutetium (record ). The element has special catalytic properties (oil industry). 176Lu is generated artificially and is a good beta emitter (research purposes). 177Lu has a half-life of six days and is used in nuclear medicine. 

Lanthanide ions offer several salient properties that make them especially attractive as qubit candidates (i) their magnetic states provide proper definitions of the qubit basis (ii) they show reasonably long coherence times (iii) important qubit parameters, such as the energy gap AE and the Rabi frequency 2R, can be chemically tuned by the design of the lanthanide co-ordination shell and (iv) the same molecular structure can be realized with many different lanthanide ions (e.g. with or without nuclear spin), thus providing further versatility for the design of spin qubits or hybrid spin registers. 

Cerium, an element in the lanthanide series, has a number of radioactive isotopes. Several of these are produced in abundance in nuclear fission reactions associated with nuclear industry operations or detonation of nuclear devices. This report summarizes our present knowledge of the relevant physical, chemical, and biological properties of radiocerium as a basis for establishing radiation protection guidelines. 

Experimental investigations of spectroscopic and other physical-chemical properties of actinides are severely hampered by their radioactive decay and radiation which lead to chemical modifications of the systems under study. The diversity of properties of lanthanide and actinide compounds is unique due to the multitude of their valency forms (which can vary over a wide range) and because of the particular importance of relativistic effects. They are, therefore, of great interest, both for fundamental research and for the development of new technologies and materials. The most important practical problems involve storage and processing of radioactive waste and nuclear fuel, as well as pollution of the environment by radioactive waste, where most of the decayed elements are actinides. 

In spite of considerable similarities between the chemical properties of lanthanides and actinides, the trivalent oxidation state is not stable for the early members of the actinide series. Due to larger ionic radii and the presence of shielding electrons, the 5f electrons of actinides are subjected to a weaker attraction from the nuclear charge than the corresponding 4f electrons of lanthanides. The greater stability of tetrapositive ions of actinides such as Th and Pu is attributed to the smaller values of fourth ionization potential for 5f electrons compared to 4f electrons of lanthanides, an effect that has been observed in aqueous solution of Th and Ce (2). Thus, thorium... 

Meridiano, Y., Berthon, L., Lagrave, S., Crozes, X., Sorel, C., Testard, F., Zemb, T. 2008. Correlation between aggregation and extracting properties in solvent extraction systems Extraction of actinides (IB) and lanthanides (III) by a malonamide in non acidic media. ATALANTE 2008 Nuclear Fuel Cycles for a Sustainable Future, May, Montpellier, France. 

This volume of the Handbook illustrates the rich variety of topics covered by rare earth science. Three chapters are devoted to the description of solid state compounds skutteru-dites (Chapter 211), rare earth-antimony systems (Chapter 212), and rare earth-manganese perovskites (Chapter 214). Two other reviews deal with solid state properties one contribution includes information on existing thermodynamic data of lanthanide trihalides (Chapter 213) while the other one describes optical properties of rare earth compounds under pressure (Chapter 217). Finally, two chapters focus on solution chemistry. The state of the art in unraveling solution structure of lanthanide-containing coordination compounds by paramagnetic nuclear magnetic resonance is outlined in Chapter 215. The potential of time-resolved, laser-induced emission spectroscopy for the analysis of lanthanide and actinide solutions is presented and critically discussed in Chapter 216. 

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