Chemistry:Tantalum arsenide
From HandWiki
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| Identifiers | |
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3D model (JSmol)
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| Properties | |
| TaAs | |
| Molar mass | 255.869 g/mol |
| Density | 12.25 g/cm3[1] |
| Melting point | Decomposes at 1400°C[2] |
| Structure | |
| Body-centered tetragonal | |
| I41md, No. 109 | |
| 4mm | |
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa). | |
| Infobox references | |
Tantalum arsenide is a compound of tantalum and arsenic with the formula TaAs. It is notable as being the first topological Weyl semimetal that was identified and characterized by ARPES.[3]
Structure
Tantalum arsenide crystallizes in a body-centered tetragonal unit cell with lattice parameters a = 3.44 Å and c = 11.65 Å. It belongs to the space group I41md.
Preparation
TaAs has been prepared by decomposing TaAs2 at 900 °C.[1] A more recent preparation yielded large, single crystals of TaAs by chemical vapor transport with elemental precursors and iodine as the transport agent:[2]
- TaI5 (g) + AsI3 (g) ↔ TaAs (s) + 4 I2 (g)
References
- ↑ 1.0 1.1 1.2 "On the Arsenides and Antimonides of Tantalum.". Acta Chemica Scandinavica 19: 95–106. 1965. doi:10.3891/acta.chem.scand.19-0095. ISSN 0904-213X.
- ↑ 2.0 2.1 2.2 "Weyl Semimetal TaAs: Crystal Growth, Morphology, and Thermodynamics". Crystal Growth & Design 16 (3): 1172–1175. 2 March 2016. doi:10.1021/acs.cgd.5b01758. ISSN 1528-7505.
- ↑ 3.0 3.1 "Discovery of a Weyl fermion semimetal and topological Fermi arcs". Science 349 (6248): 613–617. 7 August 2015. doi:10.1126/science.aaa9297. ISSN 1095-9203. PMID 26184916. Bibcode: 2015Sci...349..613X.
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