Silver telluride
Crystal structure | ||||||||||||||||
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__ Ag __ Te | ||||||||||||||||
General | ||||||||||||||||
Surname | Silver telluride | |||||||||||||||
other names |
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Ratio formula | Ag 2 Te | |||||||||||||||
Brief description |
black solid |
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External identifiers / databases | ||||||||||||||||
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properties | ||||||||||||||||
Molar mass | 343.34 g mol −1 | |||||||||||||||
Physical state |
firmly |
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density |
8.35 g cm −3 |
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Melting point |
955 ° C |
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safety instructions | ||||||||||||||||
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Thermodynamic properties | ||||||||||||||||
ΔH f 0 |
−20.9 kJ / mol |
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As far as possible and customary, SI units are used. Unless otherwise noted, the data given apply to standard conditions . |
Silver telluride (silver (I) -telluride, Ag 2 Te) is a monoclinic crystal compound from the group of tellurides , which is formed from silver and tellurium . In a broader sense, the term silver telluride also includes metastable silver (II) telluride (AgTe), also referred to in mineral form as empressite , and Ag 5 Te 3 into which the metastable silver (II) telluride breaks down.
Extraction and presentation
Silver telluride is produced by passing tellurium vapors over silver in nitrogen gas at a reaction temperature of 470 ° C.
properties
Silver telluride is a black-gray, crystalline substance. The normal β-silver telluride has a monoclinic crystal structure with the space group P 2 1 / c (space group no. 14) and lattice constants of a = 816 pm, b = 446.8 pm, c = 897.7 pm and β = 124 ° 16 '. The α-modification has a cubic crystal structure with the space group Fm 3 m (No. 225) , and forms at temperatures above 144 ° C. In addition, three high-pressure modifications are known which form at pressures of 2.4 GPa, 2.8 GPa and 12.8 GPa.
Silver telluride is a semiconductor that can be both p- doped and n-doped.
use
Silver telluride is used to manufacture tellurium because it is a by-product (in addition to gold telluride ) when processing the anode sludge in copper refining.
Individual evidence
- ^ A b Dale L. Perry: Handbook of Inorganic Compounds, Second Edition . CRC Press, 2011, pp. 486 ( limited preview in Google Book search).
- ↑ a b c data sheet Silver (I) telluride from Sigma-Aldrich , accessed on August 7, 2011 ( PDF ).
- ↑ a b c Georg Brauer (ed.), With the collaboration of Marianne Baudler a . a .: Handbook of Preparative Inorganic Chemistry. 3rd, revised edition. Volume II, Ferdinand Enke, Stuttgart 1978, ISBN 3-432-87813-3 , p. 1001.
- ^ A. van der Lee, JL de Boer: Redetermination of the structure of hessite, Ag 2 Te-III. In: Acta Crystallographica Section C Crystal Structure Communications. 49, pp. 1444-1446, doi : 10.1107 / S0108270193003294 .
- ↑ Zhao Zhao, Shibing Wang, Haijun Zhang, Wendy L. Mao: Pressure-induced structural transitions and metallization in Ag 2 Te. In: Physical Review B. 88, 2013, S., doi : 10.1103 / PhysRevB.88.024120 .
- ↑ Seilnacht: Tellurium