neodymium(III) oxide
{{chembox
| Watchedfields = changed
| verifiedrevid = 439303620
| Name = Neodymium(III) oxide
| ImageFile = La2O3structure.svg
| ImageSize =
| ImageName =
| ImageFile2 = Neodymium oxide 170g.jpg
| IUPACName = Neodymium(III) oxide
| OtherNames = Neodymium oxide, Neodymium sesquioxide
|Section1={{Chembox Identifiers
| CASNo_Ref = {{cascite|correct|CAS}}
| CASNo = 1313-97-9
| UNII_Ref = {{fdacite|correct|FDA}}
| UNII = AYT3H319PN
| PubChem = 4196641
| RTECS =
| EINECS = 215-214-1
| DTXSID = DTXSID2051479
| ChemSpiderID = 3407022
| StdInChI=1S/2Nd.3O
| StdInChIKey = HBPPDPSYLUIKHU-UHFFFAOYSA-N
| SMILES = O=[Nd]O[Nd]=O
}}
|Section2={{Chembox Properties
| Formula = Nd2O3
| MolarMass = 336.48 g/mol
| Appearance = light bluish gray hexagonal crystals
| Density = 7.24 g/cm3
| Solubility = .0003 g/100 mL (75 °C)
| MeltingPtC = 2233
| BoilingPtC = 3760
{{Citation
| last = Lide
| first = David R.
| year = 1998
| title = Handbook of Chemistry and Physics
| edition = 87
| publication-place = Boca Raton, FL
| publisher = CRC Press
| isbn = 0-8493-0594-2
| pages = 471; 552
}}
| MagSus = +10,200.0·10−6 cm3/mol
}}
|Section3={{Chembox Structure
| CrystalStruct = Hexagonal, hP5
| SpaceGroup = P-3m1, No. 164
}}
|Section4={{Chembox Thermochemistry
| DeltaHf = −1807.9 kJ·mol−1
| DeltaHc =
| Entropy = 158.6 J·mol−1·K−1
| HeatCapacity = 111.3 J·mol−1·K−1
}}
|Section7={{Chembox Hazards
| FlashPt =
}}
|Section8={{Chembox Related
| OtherAnions = Neodymium(II) chloride
Neodymium(III) chloride
| OtherCations = Uranium(VI) oxide
Praseodymium(III) oxide
Promethium(III) oxide
}}
}}
Neodymium(III) oxide or neodymium sesquioxide is the chemical compound composed of neodymium and oxygen with the formula Nd2O3. It forms very light grayish-blue hexagonal crystals. The rare-earth mixture didymium, previously believed to be an element, partially consists of neodymium(III) oxide.
{{Citation
| last1 = Brady
| first1 = George Stuart
| last2 = Clauser
| first2 = Henry R.
| last3 = Vaccari
| first3 = John A.
| year = 2002
| title = Materials Handbook
| edition = 15
| publication-place = New York
| publisher = McGraw-Hill Professional
| isbn = 978-0-07-136076-0
| pages = 779
| url = https://books.google.com/books?id=vIhvSQLhhMEC&dq=%22Neodymium+oxide%22&pg=PA779
| access-date = 2009-03-18
}}
Uses
Neodymium(III) oxide is used to dope glass, including sunglasses, to make solid-state lasers, and to color glasses and enamels.
{{Citation
| last = Eagleson
| first = Mary
| year = 1994
| title = Concise Encyclopedia of Chemistry
| publisher = Springer
| isbn = 978-3-11-011451-5
| pages = 680
| url = https://books.google.com/books?id=Owuv-c9L_IMC&dq=%22Neodymium(III)+oxide%22&pg=PA680
| access-date = 2009-03-18
}} Neodymium-doped glass turns purple due to the absorbance of yellow and green light, and is used in welding goggles.
{{Citation
| last = Emsley
| first = John
| year = 2003
| title = Nature's Building Blocks
| publisher = Oxford University Press
| isbn = 978-0-19-850340-8
| pages = 268–9
| url = https://books.google.com/books?id=j-Xu07p3cKwC&dq=%22Neodymium+oxide%22&pg=PA268
| access-date = 2009-03-18
}} 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.
{{Citation
| last = Bray
| first = Charles
| year = 2001
| title = Dictionary of Glass
| edition = 2
| publisher = University of Pennsylvania Press
| isbn = 978-0-8122-3619-4
| pages = 103
| url = https://books.google.com/books?id=KbZkxDyeG18C&dq=%22Neodymium+oxide%22&pg=PA102
| access-date = 2009-03-18
}}
About 7000 tonnes of neodymium(III) oxide are produced worldwide each year. Neodymium(III) oxide is also used as a polymerization catalyst.
Reactions
Neodymium(III) oxide is formed when neodymium(III) nitride or neodymium(III) hydroxide is roasted in air.
{{Citation
| last = Spencer
| first = James Frederick
| year = 1919
| title = The Metals of the Rare Earths
| publication-place = London
| publisher = Longmans, Green, and Co
| pages = 115
| url = https://books.google.com/books?id=W2zxN_FLQm8C&dq=%22Neodymium+oxide%22&pg=PA115
| access-date = 2009-03-18
}}
Structure
Neodymium(III) oxide has a low-temperature trigonal A form in space group P{{overline|3}}m1.{{ cite journal | author = D. Taylor | title = Thermal Expansion Data: III Sesquioxides, U2N3, with the corundum and the A-, B- and C-M2O3 structures| journal = Trans. J. Br. Ceram. Soc. | year = 1984 | volume = 83 | pages = 92–98 }} This structure type is favoured by the early lanthanides.{{Greenwood&Earnshaw2nd|page=1238-1239}}{{ cite book | author = A. F. Wells | title = Structural Inorganic Chemistry | edition = 5th | pages = 544–547 | publisher = Oxford University Press | year = 1984 }} At higher temperatures it adopts two other forms, the hexagonal H form in space group P63/mmc and the cubic X form in Im{{overline|3}}m. The high-temperature forms exhibit crystallographic disorder.{{ cite journal | title = Zur Struktur der A-Form der Sesquioxide der Seltenen Erden. II. Strukturuntersuchung an Nd2O3 | first1 = H. | last1 = Müller-Buschbaum | journal = Z. Anorg. Allg. Chem. | volume = 343 | issue = 1–2 | year = 1966 | pages = 6–10 | doi = 10.1002/zaac.19663430103 }}{{ cite journal | first1 = P. | last1 = Aldebert | first2 = J. P. | last2 = Traverse | title = Etude par diffraction neutronique des structures de haute temperature de La2O3 et Nd2O3 | journal = Mater. Res. Bull. | volume = 14 | issue = 3 | year = 1979 | pages = 303–323 | doi = 10.1016/0025-5408(79)90095-3 }}
| class="wikitable" style="text-align:center;"
|+Crystal structure of the A form of neodymium(III) oxide |
| Packing
! Neodymium coordination ! Oxygen O1 coordination ! Oxygen O2 coordination |
|---|
| 150px
| 150px | 150px | 150px |
| A-M2O3 structure type
| approximately capped octahedral | approximately tetrahedral |
References
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{{neodymium compounds}}
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{{DEFAULTSORT:Neodymium(Iii) Oxide}}