Ytterbium lanthanide metals lutetium

The primary reason for distillation/sublimation as a purification process is to separate the non-volatile tantalum from the higher melting lanthanide metals gadolinium through erbium, plus lutetium, and scandium and yttrium. As explained earlier samarium, europium and ytterbium are prepared in a vacuum process that involves their distillation from the reaction mixture they may be re-sublimed to achieve a higher purity. 

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. 

Recently, rare-earth metal complexes have attracted considerable attention as initiators for the preparation of PLA via ROP of lactides, and promising results were reported in most cases [94—100]. Group 3 members (e.g. scandium, yttrium) and lanthanides such as lutetium, ytterbium, and samarium have been frequently used to develop catalysts for the ROP of lactide. The principal objectives of applying rare-earth complexes as initiators for the preparation of PLAs were to investigate (1) how the spectator ligands would affect the polymerization dynamics (i.e., reaction kinetics, polymer composition, etc.), and (2) the relative catalytic efficiency of lanthanide(II) and (III) towards ROPs. 

Here, the so-called heavy lanthanides include the elements from samarium to-lutetium, except for ytterbium and europium which behave like bivalent metals and have unique properties. For these heavy-lanthanide-carbon systems, no complete phase diagram was found, only some information about the formation and the crystal structure of the carbides is available. On the basis of these data the general characteristics of the phase diagrams of the heavy-rare-earth-carbon systems can be summarized. In this case the yttrium-carbon phase diagram may be regarded as the best prototype available for compounds of the heavy lanthanide systems with carbon. 

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