Tin_telluride Knowpia

Tin telluride^[1]
Names
	IUPAC name Tin telluride
	Other names Tin(II) telluride, Stannous telluride
Identifiers
CAS Number	12040-02-7 ;
3D model (JSmol)	Interactive image;
ECHA InfoCard	100.031.728
PubChem CID	6432000;
CompTox Dashboard (EPA)	DTXSID40894844 ;
	InChI InChI=1S/Sn.Te;
	SMILES [Sn]=[Te];
Properties
Chemical formula	SnTe
Molar mass	246.31 g/mol
Appearance	gray cubic crystals
Density	6.445 g/cm3
Melting point	790 °C (1,450 °F; 1,060 K)
Band gap	0.18 eV
Electron mobility	500 cm2 V−1 s−1
Structure
Crystal structure	Halite (cubic), cF8
Space group	Fm3m, No. 225
Lattice constant	a = 0.63 nm
Coordination geometry	Octahedral (Sn2+); Octahedral (Se2−)
Thermochemistry
Heat capacity (C)	185 J K−1 kg−1
Related compounds
Other anions	Tin(II) oxide; Tin(II) sulfide; Tin selenide
Other cations	Carbon monotelluride; Silicon monotelluride; Germanium telluride; Lead telluride
	Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa). verify (what is ?) Infobox references

Tin telluride is a compound of tin and tellurium (SnTe); is a IV-VI narrow band gap semiconductor and has direct band gap of 0.18 eV. It is often alloyed with lead to make lead tin telluride, which is used as an infrared detector material.

Tin telluride normally forms p-type semiconductor (Extrinsic semiconductor) due to tin vacancies and is a low temperature superconductor.^[4]

SnTe exists in three crystal phases. At Low temperatures, where the concentration of hole carriers is less than 1.5x10²⁰ cm⁻³ , Tin Telluride exists in rhombohedral phase also known as α-SnTe. At room temperature and atmospheric pressure, Tin Telluride exists in NaCl-like cubic crystal phase, known as β-SnTe. While at 18 kbar pressure, β-SnTe transforms to γ-SnTe, orthorhombic phase, space group Pnma.^[5] This phase change is characterized by 11 percent increase in density and 360 percent increase in resistance for γ-SnTe.^[6]

Tin telluride is a thermoelectric material. Theoretical studies imply that the n-type performance may be particularly good.^[7]

Thermal properties edit

Standard enthalpy of formation: - 14.6 ± 0.3 kcal/mole at 298 K
Standard Enthalpy of sublimation: 52.1 ± 1.4 kcal/mole at 298 K
Heat capacity: 12.1 + 2.1 x 10⁻³ T cal/deg
Bond-dissociation energy for the reaction SnTe(g)-> Sn(g)+ Te(g) : 80.6 ± 1.5 kcal/mole at 298 K
Entropy: 24.2±0.1 cal/mole.deg
Enthalpy of Dimerization for the reaction Sn₂Te₂->2SnTe(g) :46.9 ± 6.0 kcal/mole ^[8]

Applications edit

Generally Pb is alloyed with SnTe in order to access interesting optical and electronic properties, In addition, as a result of Quantum confinement, the band gap of the SnTe increases beyond the bulk band gap, covering the mid-IR wavelength range. The alloyed material has been used in mid- IR photodetectors ^[9] and thermoelectric generator.^[10]

References edit

^ Lide, David R. (1998), Handbook of Chemistry and Physics (87 ed.), Boca Raton, FL: CRC Press, pp. 4–90, ISBN 978-0-8493-0594-8
^ Beattie, A. G., J. Appl. Phys., 40, 4818–4821, 1969.
^ O. Madelung, U. Rössler, M. Schulz; SpringerMaterials; sm_lbs_978-3-540-31360-1_859 (Springer-Verlag GmbH, Heidelberg, 1998), http://materials.springer.com/lb/docs/sm_lbs_978-3-540-31360-1_859;
^ Hein, R.; Meijer, P. (1969). "Critical Magnetic Fields of Superconducting SnTe". Physical Review. 179 (2): 497. Bibcode:1969PhRv..179..497H. doi:10.1103/PhysRev.179.497.
^ "Tin telluride (Sn Te) crystal structure, lattice parameters". Non-Tetrahedrally Bonded Elements and Binary Compounds I. Landolt-Börnstein - Group III Condensed Matter. Vol. 41C. 1998. pp. 1–8. doi:10.1007/10681727_862. ISBN 978-3-540-64583-2.
^ Kafalas, J. A.; Mariano, A. N., High-Pressure Phase Transition in Tin Telluride. Science 1964, 143 (3609), 952-952
^ Singh, D. J. (2010). "THERMOPOWER OF SnTe FROM BOLTZMANN TRANSPORT CALCULATIONS". Functional Materials Letters. 03 (4): 223–226. arXiv:1006.4151. doi:10.1142/S1793604710001299. S2CID 119223416.
^ Colin, R.; Drowart, J., Thermodynamic study of tin selenide and tin telluride using a mass spectrometer. Transactions of the Faraday Society 1964, 60 (0), 673-683, DOI: 10.1039/TF9646000673.
^ Lovett, D. R. Semimetals and narrow-bandgap semiconductors; Pion Limited: London, 1977; Chapter 7.
^ Das, V. D.; Bahulayan, C., Variation of electrical transport properties and thermoelectric figure of merit with thickness in 1% excess Te-doped Pb 0.2 Sn 0.8 Te thin films. Semiconductor Science and Technology 1995, 10 (12), 1638.