Neodymium

Neodymium is a chemical element with the symbol Nd and atomic number 60. It is a silvery-white metal belonging to the lanthanide series and is one of the rare-earth elements. The metal tarnishes in air and reacts with water. Its compounds predominantly contain neodymium in the +3 oxidation state, although +2 and +4 compounds are also known. Natural neodymium contains seven isotopes, two of which are radioactive with extremely long half-lives. The Austrian chemist Carl Auer von Welsbach discovered neodymium in 1885 when he separated didymium, previously regarded as an element, into neodymium and praseodymium. Its name derives from the Greek for 'new twin'. Neodymium occurs with other rare-earth elements in minerals such as bastnäsite and monazite, from which it is separated during refining. China is the largest producer and refiner of the rare-earth elements used in magnets, including neodymium. Neodymium is used in neodymium–iron–boron magnets, which produce strong magnetic fields from small, lightweight components. These permanent magnets are used in audio equipment, computer hard disk drives, electric vehicle motors and the generators of some wind turbines. Neodymium compounds are also used as catalysts in the manufacture of synthetic rubber. Neodymium imparts color to glass and is used in decorative glassware and optical filters. Its selective absorption of light can make the glass appear different colors under different illumination. Neodymium ions also provide the active component in solid-state lasers, including Nd:YAG lasers and neodymium-glass lasers, used in manufacturing, medicine and inertial confinement fusion research. Neodymium isotope ratios are used in dating rocks and tracing geological processes and past ocean circulation. Neodymium can serve as an enzyme cofactor in certain bacteria, while finely divided metal and powerful neodymium magnets present chemical and physical hazards.