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The Gmelin rare earths handbook lists 1522 °C and 1550 °C as two melting points given in the literature, the most recent reference [Handbook on the chemistry and physics of rare earths, vol.12 (1989)] is given with 1529 °C. The World Book encyclopedia from 2002 lists 1529 °C. WEL: 1770 K: 1497 °C: 2727 °F CRC: 1529 °C: LNG: 1529 °C: 69 ...
The rare-earth elements (REE), also called the rare-earth metals or rare earths, and sometimes the lanthanides or lanthanoids (although scandium and yttrium, which do not belong to this series, are usually included as rare earths), [1] are a set of 17 nearly indistinguishable lustrous silvery-white soft heavy metals. Compounds containing rare ...
These values depend on temperature, pressure, and composition of the mineral melt. D {\displaystyle D} values differ considerably between major elements and trace elements. By definition, incompatible trace elements have an equilibrium constant value of less than one because trace elements have higher concentrations in the melt than solids. [ 1 ]
The term rare-earth element or rare-earth metal is often used to include the stable group 3 elements Sc, Y, and Lu in addition to the 4f elements. [8] All lanthanide elements form trivalent cations, Ln 3+ , whose chemistry is largely determined by the ionic radius , which decreases steadily from lanthanum (La) to lutetium (Lu).
Starting from the bottom left, and proceeding clockwise, the alkali metals are followed by the heavier alkaline earth metals; the rare earths and actinides (Sc, Y and the lanthanides being here treated as rare earths); transition metals with intermediate electronegativity values and melting points; the refractory metals; the platinum group ...
The two are both rare-earth fluorocarbonates, but parisite's formula of Ca(Ce, La, Nd) 2 (CO 3) 3 F 2 contains calcium (and a small amount of neodymium) and a different ratio of constituent ions. Parisite could be viewed as a formula unit of calcite (CaCO 3 ) added to two formula units of bastnäsite.
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As most other oxides of rare-earth elements, holmium oxide is used as a specialty catalyst, phosphor and a laser material. Holmium laser operates at wavelength of about 2.08 micrometres, either in pulsed or continuous regime. This laser is eye safe and is used in medicine, lidars, wind velocity measurements and atmosphere monitoring. [15]