United States dysprosium

Paris by the French scientist Paul-Emile Lecoq de Boisbaudran. Its isolation was made possible by the development of ion-exchange separation in the 1950s. Dysprosium belongs to a series of elements called rare earths, lanthanides, or 4f elements. The occurrence of dysprosium is low 4.5 ppm (parts per million), that is, 4.5 grams per metric ton in Earth s crust, and 2 x 10 7 ppm in seawater. Two minerals that contain many of the rare earth elements (including dysprosium) are commercially important mon-azite (found in Australia, Brazil, India, Malaysia, and South Africa) and bast-nasite (found in China and the United States). As a metal, dysprosium is reactive and yields easily oxides or salts of its triply oxidized form (Dy3+ ion). 

REEs are classified as lithophiles and are partitioned into the earth s crust and mantle. The name rare earths originated over a century ago when the elements were first identified in minerals that, at the time, were rare. The elements are actually distributed widely over the earth and relatively accessible on the earth s surface. For a comprehensive description of REE geology, geochemistry, and natural abundances, see Geology, Geochemistry, and Natural Abundances of the Rare Earth Elements. In 2010, the United States Geological Survey (USGS) estimated that there were REE reserves of 110 million metric tons (mt). The static depletion index, the ratio of reserves to present-day production, for REEs is approximately 870 years. Thus, the primary immediate consideration is whether REE production can match demand, and particularly whether it will be possible to increase the use of dysprosium and neodymium in wind turbines and the batteries of electric vehicles. 

The lattice parameter of the compounds R3 MC in the lanthanide series for a given element M changes linearly with the radius of the trivalent rare earth ions, following the lanthanide contraction regularity, except for europium and ytterbium which appear to have a variable-valence state. In the ytterbium-M (Al, Ga, In, Tl)-carbon system, the unit cell volume of the compound YbgMC, is larger than the value expected from the relationship mentioned above. In the europium-M(Al, Ga, In, Tl)-carbon system no compound was found. For the compounds of yttrium, as expected, the lattice parameter falls between those of the respective terbium and dysprosium compounds. 

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