Neodymium(III) oxide is used to dope glass, including sunglasses, to make solid-state lasers, and to color glasses and enamels.[3] Neodymium-doped glass turns purple due to the absorbance of yellow and green light, and is used in weldinggoggles.[4] Some neodymium-doped glass is dichroic; that is, it changes color depending on the lighting. One kind of glass named for the mineral alexandrite appears blue in sunlight and red in artificial light.[5]
About 7000 tonnes of neodymium(III) oxide are produced worldwide each year. Neodymium(III) oxide is also used as a polymerizationcatalyst.[4]
Neodymium(III) oxide has a low-temperature trigonal A form in space group P3m1.[7] This structure type is favoured by the early lanthanides.[8][9] At higher temperatures it adopts two other forms, the hexagonal H form in space group P63/mmc and the cubic X form in Im3m. The high-temperature forms exhibit crystallographic disorder.[10][11]
Crystal structure of the A form of neodymium(III) oxide
^ abc
Lide, David R. (1998), Handbook of Chemistry and Physics (87 ed.), Boca Raton, FL: CRC Press, pp. 471, 552, ISBN0-8493-0594-2
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Brady, George Stuart; Clauser, Henry R.; Vaccari, John A. (2002), Materials Handbook (15 ed.), New York: McGraw-Hill Professional, p. 779, ISBN978-0-07-136076-0, retrieved 2009-03-18
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Spencer, James Frederick (1919), The Metals of the Rare Earths, London: Longmans, Green, and Co, p. 115, retrieved 2009-03-18
^D. Taylor (1984). "Thermal Expansion Data: III Sesquioxides, U2N3, with the corundum and the A-, B- and C-M2O3 structures". Trans. J. Br. Ceram. Soc.83: 92–98.
^Aldebert, P.; Traverse, J. P. (1979). "Etude par diffraction neutronique des structures de haute temperature de La2O3 et Nd2O3". Mater. Res. Bull.14 (3): 303–323. doi:10.1016/0025-5408(79)90095-3.