Tantalum arsenide

Tantalum arsenide
Identifiers
Ta As
3D model (JSmol)	Interactive image
InChI InChI=1S/As.Ta Key: WCMKFCQUZDOHAQ-UHFFFAOYSA-N
SMILES [As]#[Ta]
Properties
Chemical formula	TaAs
Molar mass	255.869 g/mol
Density	12.25 g/cm³^[1]
Melting point	Decomposes at 1400°C^[2]
Structure
Crystal structure	Body-centered tetragonal
Space group	I4₁md, No. 109
Point group	4mm
Lattice constant	a = 3.44 Å, c = 11.65 Å^[1]^[2]^[3]
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa). Infobox references

Chemical compound

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

^ ^a ^b ^c Furuseth, S., Selte, K., Kjekshus, A., Gronowitz, S., Hoffman, R. A., Westerdahl, A. (1965). "On the Arsenides and Antimonides of Tantalum". Acta Chemica Scandinavica. 19: 95–106. doi:10.3891/acta.chem.scand.19-0095. ISSN 0904-213X.
^ ^a ^b ^c Li, Z., Chen, H., Jin, S., Gan, D., Wang, W., Guo, L., Chen, X. (2 March 2016). "Weyl Semimetal TaAs: Crystal Growth, Morphology, and Thermodynamics". Crystal Growth & Design. 16 (3): 1172–1175. doi:10.1021/acs.cgd.5b01758. ISSN 1528-7505.
^ ^a ^b Xu, S.-Y., Belopolski, I., Alidoust, N., Neupane, M., Bian, G., Zhang, C., Sankar, R., Chang, G., Yuan, Z., Lee, C.-C., Huang, S.-M., Zheng, H., Ma, J., Sanchez, D. S., Wang, B., Bansil, A., Chou, F., Shibayev, P. P., Lin, H., Jia, S., Hasan, M. Z. (7 August 2015). "Discovery of a Weyl fermion semimetal and topological Fermi arcs". Science. 349 (6248): 613–617. arXiv:1502.03807. Bibcode:2015Sci...349..613X. doi:10.1126/science.aaa9297. ISSN 1095-9203. PMID 26184916. S2CID 206636457.