yb体育官网 - yb体育登陆

Rare Earth

ABT Rare Earth

Rare earth element (REE) or rare earth metal (REM), as defined by IUPAC, is one of a set of seventeen chemical elements in the periodic table, specifically the fifteen lanthanides, as well as scandium and yttium. Scandium and yttrium are considered rare earth elements because they tend to occur in the same ore deposits as the lanthanides and exhibit similar chemical properties.

Despite their name, rare earth elements are – with the exception of the radioactive promethium – relatively plentiful in Earth's crust, with cerium being the 25th most abundant element at 68 parts per million, or as abundant as copper. However, because of their geochemical properties, rare earth elements are typically dispersed and not often found concentrated as rare earth minerals in economically exploitable ore deposits. It was the very scarcity of these minerals (previously called "earths") that led to the term "rare earth". The first such mineral discovered was gadolinite, a mineral composed of cerium, yttrium, iron, silicon and other elements. This mineral was extracted from a mine in the village of Ytterby in Sweden; four of the rare earth elements bear names derived from this single location.

 

Z Symbol Name Etymology Selected applications
21 Sc Scandium from Latin Scandia (Scandinavia). Light aluminium-scandium alloys for aerospace components, additive in metal-halide lamps and mercury-vapor lamps,[4] radioactive tracing agent in oil refineries
39 Y Yttrium after the village of Ytterby, Sweden, where the first rare earth ore was discovered. Yttrium aluminium garnet (YAG) laser, yttrium vanadate (YVO4) as host for europium in television red phosphor, YBCO high-temperature superconductors, yttria-stabilized zirconia (YSZ), yttrium iron garnet (YIG) microwave filters,[4] energy-efficient light bulbs,[5] spark plugs, gas mantles, additive to steel
57 La Lanthanum from the Greek "lanthanein", meaning to be hidden. High refractive index and alkali-resistant glass, flint, hydrogen storage, battery-electrodes, camera lenses, fluid catalytic cracking catalyst for oil refineries
58 Ce Cerium after the dwarf planet Ceres, named afterthe Roman goddess of agriculture. Chemical oxidizing agent, polishing powder, yellow colors in glass and ceramics, catalyst for self-cleaning ovens, fluid catalytic cracking catalyst for oil refineries, ferrocerium flints for lighters
59 Pr Praseodymium from the Greek "prasios", meaning leek-green, and "didymos", meaning twin. Rare-earth magnets, lasers, core material for carbon arc lighting, colorant in glasses and enamels, additive in didymium glass used in welding goggles,[4]ferrocerium firesteel (flint) products.
60 Nd Neodymium from the Greek "neos", meaning new, and "didymos", meaning twin. Rare-earth magnets, lasers, violet colors in glass and ceramics, didymium glass, ceramic capacitors
61 Pm Promethium after the Titan Prometheus, who brought fire to mortals. Nuclear batteries, luminous paint
62 Sm Samarium after mine official, Vasili Samarsky-Bykhovets. Rare-earth magnets, lasers, neutron capture, masers
63 Eu Europium after the continent of Europe. Red and blue phosphors, lasers, mercury-vapor lamps, fluorescent lamps, NMR relaxation agent
64 Gd Gadolinium after Johan Gadolin (1760–1852), to honor his investigation of rare earths. High refractive index glass or garnets, lasers, X-ray tubes, computer memories, neutron capture, MRI contrast agent, NMR relaxation agent, magnetostrictive alloyssuch as Galfenol, steel additive
65 Tb Terbium after the village of Ytterby, Sweden. Additive in Neodymium based magnets, Green phosphors, lasers, fluorescent lamps, magnetostrictive alloys such as Terfenol-D
66 Dy Dysprosium from the Greek "dysprositos", meaning hard to get. Additive in Neodymium based magnets, lasers, magnetostrictive alloys such as Terfenol-D
67 Ho Holmium after Stockholm (in Latin, "Holmia"), native city of one of its discoverers. Lasers, wavelength calibration standards for optical spectrophotometers, magnets
68 Er Erbium after the village of Ytterby, Sweden. Infrared lasers, vanadium steel, fiber-optic technology
69 Tm Thulium after the mythological northern land ofThule. Portable X-ray machines, metal-halide lamps, lasers
70 Yb Ytterbium after the village of Ytterby, Sweden. Infrared lasers, chemical reducing agent, decoy flares, stainless steel, stress gauges, nuclear medicine
71 Lu Lutetium after Lutetia, the city that later becameParis. Positron emission tomography – PET scan detectors, high-refractive-index glass, lutetium tantalate hosts for phosphors