Scandium dodecaboride

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IUPACName = scandium dodecaboride
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Formula = ScB₁₂
MolarMass = 174.69 g/mol
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Scandium dodecaboride is a refractory metal boride.

Synthesis

ScB₁₂ is formed by mixing a 7:1 ratio of boron powder and scandium oxide powder, heating to 2500 °C with a plasma torch or similar, quenching in cold water and washing with concentrated hydrochloric acid.cite journal |last=Matkovich |first=V.I.|coauthors= J Economy, R F Giese Jr, R Barrett|year= 1965 |title= The structure of metallic dodecaborides|journal= Acta Cryst.|volume=19 |pages=1056-1058 |doi=10.1107/S0365110X65004954|url=http://journals.iucr.org/q/issues/1965/12/00/a04941/a04941.pdf |accessdate=2008-08-28 ]

Crystallography

ScB₁₂ was originally reported as having a cubic structure, [cite journal |last= Przybylska|first= Maria|coauthors= Allan H. Reddoch, George J. Ritter|year= 1963 |title= The Preparation and Structure of Lutetium Diboride, Scandium Dodecaboride and Lutetium Antimonide |journal= J. Am. Chem. Soc|volume=85 |isuue= 4|pages=407-411 |doi= 10.1021/ja00887a008 ] later studies showed it to have tetragonal structure (unit cell with a=522pm, c=735pm). More recently it has been shown that there is indeed a cubic form but that it requires stabilisation. [cite journal |last=Paderno |first=Y.|coauthors=N. Shitsevalova |year= 1995 |title= Stabilization of cubic scandium dodecaboride|journal= Journal of Alloys and Compounds|volume=219 |issue=1-2|pages=119-123|doi=10.1016/0925-8388(94)05048-1 ]

References