Rare Earth Elements List

This is a list of rare earth elements (REEs), which are a special group of metals.

The CRC Handbook of Chemistry and Physics and IUPAC list the rare earths as consisting of the lanthanides, plus scandium and yttrium. This includes atomic number 57 through 71, as well as 39 (yttrium) and 21 (scandium):

Lanthanum (sometimes considered a transition metal)
Cerium
Praseodymium
Neodymium
Promethium
Samarium
Europium
Gadolinium
Terbium
Dysprosium
Holmium
Erbium
Thulium
Ytterbium
Lutetium
Scandium
Yttrium

Other sources consider the rare earths to be the lanthanides and actinides:

Lanthanum (sometimes considered a transition metal)
Cerium
Praseodymium
Neodymium
Promethium
Samarium
Europium
Gadolinium
Terbium
Dysprosium
Holmium
Erbium
Thulium
Ytterbium
Lutetium
Actinium (sometimes considered a transition metal)
Thorium
Protactinium
Uranium
Neptunium
Plutonium
Americium
Curium
Berkelium
Californium
Einsteinium
Fermium
Mendelevium
Nobelium
Lawrencium

Classification of Rare Earths

The classification of the rare earth elements is as hotly disputed as the list of included metals. One common method of classification is by atomic weight. Low atomic weight elements are the light rare earth elements (LREEs). Elements with high atomic weight are the heavy rare earth elements (HREEs). Elements that fall between the two extremes are the middle rare earth elements (MREEs). One popular system categorizes atomic numbers up to 61 as LREEs and those higher than 62 as HREEs (with the middle range absent or up to interpretation).

Summary of Abbreviations

Several abbreviations are used in connection with the rare earth elements:

• RE: rare earth
• REE: rare earth element
• REM: rare earth metal
• REO: rare earth oxide
• REY: rare earth element and yttrium
• LREE: light rare earth elements
• MREE: middle rare earth elements
• HREE: heavy rare earth elements

Rare Earth Uses

In general, the rare earths are used in alloys, for their special optical properties, and in electronics. Some specific uses of elements include:

• Scandium: Use to make light alloys for the aerospace industry, as a radioactive tracer, and in lamps
• Yttrium: Used in yttrium aluminum garnet (YAG) lasers, as a red phosphor, in superconductors, in fluorescent tubes, in LEDs, and as a cancer treatment
• Lanthanum: Use to make high refractive index glass, camera lenses, and catalysts
• Cerium: Use to impart a yellow color to glass, as a catalyst, as a polishing powder, and to make flints
• Praseodymium: Used in lasers, arc lighting, magnets, flint steel, and as a glass colorant
• Neodymium: Used to impart violet color to glass and ceramics, in lasers, magnets, capacitors, and electric motors
• Promethium: Used in luminous paint and nuclear batteries
• Samarium: Used in lasers, rare earth magnets, masers, nuclear reactor control rods
• Europium: Used to prepare red and blue phosphors, in lasers, in fluorescent lamps, and as an NMR relaxant
• Gadolinium: Used in lasers, x-ray tubes, computer memory, high refractive index glass, NMR relaxation, neutron capture, MRI contrast
• Terbium: Use in green phosphors, magnets, lasers, fluorescent lamps, magnetostrictive alloys, and sonar systems
• Dysprosium: Used in hard drive disks, magnetostrictive alloys, lasers, and magnets
• Holmium: Use in lasers, magnets, and calibration of spectrophotometers
• Erbium: Used in vanadium steel, infrared lasers, and fiber optics
• Thulium: Used in lasers, metal halide lamps, and portable x-ray machines
• Ytterbium: Used in infrared lasers, stainless steel, and nuclear medicine
• Lutetium: Used in positron emission tomography (PET) scans, high refractive index glass, catalysts, and LEDs

Sources

• Brownlow, Arthur H. (1996). Geochemistry. Upper Saddle River, N.J.: Prentice Hall. ISBN 978-0133982725.
• Connelly, N. G. and T. Damhus, ed. (2005). Nomenclature of Inorganic Chemistry: IUPAC Recommendations 2005. With R. M. Hartshorn and A. T. Hutton. Cambridge: RSC Publishing. ISBN 978-0-85404-438-2.
• Hammond, C. R. (2009). "Section 4; The Elements". In David R. Lide (ed.). CRC Handbook of Chemistry and Physics, 89th ed. Boca Raton, FL: CRC Press/Taylor and Francis.
• Jébrak, Michel; Marcoux, Eric; Laithier, Michelle; Skipwith, Patrick (2014). Geology of mineral resources (2nd ed.). St. John's, NL: Geological Association of Canada. ISBN 9781897095737.
• Ullmann, Fritz, ed. (2003). Ullmann's Encyclopedia of Industrial Chemistry. 31. Contributor: Matthias Bohnet (6th ed.). Wiley-VCH. p. 24. ISBN 978-3-527-30385-4.