Scandium dodecaboride

From Wikipedia, the free encyclopedia
Jump to: navigation, search
Scandium dodecaboride
ScB12structure.jpg
Properties
Molecular formula ScB12
Molar mass 174.69 g/mol
Structure
Crystal structure Tetragonal, tI26
Space group I4/mmm, No. 139
Except where noted otherwise, data are given for materials in their standard state (at 25 °C (77 °F), 100 kPa)
 YesY (verify) (what is: YesY/N?)
Infobox references

Scandium dodecaboride is a refractory metal boride.

Synthesis[edit]

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.[1]

Crystallography[edit]

ScB12 was originally reported as having a cubic structure,[2] later studies showed it to have tetragonal structure (unit cell with a=522pm, c=735pm).[1] More recently it has been shown that there is indeed a cubic form but that it requires stabilization.[3]

References[edit]

  1. ^ a b Matkovich, V.I.; J Economy; R F Giese Jr; R Barrett (1965). "The structure of metallic dodecaborides". Acta Cryst. 19 (6): 1056–1058. doi:10.1107/S0365110X65004954. Retrieved 2008-08-28. 
  2. ^ Przybylska, Maria; Allan H. Reddoch; George J. Ritter (1963). "The Preparation and Structure of Lutetium Diboride, Scandium Dodecaboride and Lutetium Antimonide". J. Am. Chem. Soc 85 (4): 407–411. doi:10.1021/ja00887a008. 
  3. ^ Paderno, Y.; N. Shitsevalova (1995). "Stabilization of cubic scandium dodecaboride". Journal of Alloys and Compounds 219 (1–2): 119–123. doi:10.1016/0925-8388(94)05048-1.