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Title: Crystal structure, electronic structure and physical properties of the new low-valent thallium silicon telluride Tl{sub 6}Si{sub 2}Te{sub 6} in comparison to Tl{sub 6}Ge{sub 2}Te{sub 6}

Abstract

The title compounds were prepared from the elements in the stoichiometric ratio at 800deg. C under exclusion of air. Tl{sub 6}Si{sub 2}Te{sub 6} crystallizes in the space group P1-bar , isostructural with Tl{sub 6}Ge{sub 2}Te{sub 6}, with a=9.4235(6)A, b=9.6606(7)A, c=10.3889(7)A, {alpha}=89.158(2){sup o}, {beta}=96.544(2){sup o}, {gamma}=100.685(2){sup o}, V=923.3(1)A{sup 3} (Z=2). Its structure is composed of dimeric [Si{sub 2}Te{sub 6}]{sup 6-} units with a Si-Si single bond, while the Tl atoms are irregularly coordinated by five to six Te atoms. Numerous weakly bonding Tl-Tl contacts exist. Both title compounds are black semiconductors with small band gaps, calculated to be 0.9eV for Tl{sub 6}Si{sub 2}Te{sub 6} and 0.5eV for Tl{sub 6}Ge{sub 2}Te{sub 6}. The Seebeck coefficients are +65{mu}VK{sup -1} in case of Tl{sub 6}Si{sub 2}Te{sub 6} and +150{mu}VK{sup -1} in case of Tl{sub 6}Ge{sub 2}Te{sub 6} at 300K, and the electrical conductivities are 5.5 and 3{omega}{sup -1}cm{sup -1}, respectively.

Authors:
 [1];  [1];  [2]
  1. Department of Chemistry, University of Waterloo, Waterloo, Ont., N2L 3G1 (Canada)
  2. Department of Chemistry, University of Waterloo, Waterloo, Ont., N2L 3G1 (Canada). E-mail: kleinke@uwaterloo.ca
Publication Date:
OSTI Identifier:
20905427
Resource Type:
Journal Article
Resource Relation:
Journal Name: Journal of Solid State Chemistry; Journal Volume: 179; Journal Issue: 8; Other Information: DOI: 10.1016/j.jssc.2006.05.029; PII: S0022-4596(06)00317-3; Copyright (c) 2006 Elsevier Science B.V., Amsterdam, The Netherlands, All rights reserved; Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
36 MATERIALS SCIENCE; COMPARATIVE EVALUATIONS; ELECTRIC CONDUCTIVITY; ELECTRONIC STRUCTURE; SEMICONDUCTOR MATERIALS; SILICIDES; SPACE GROUPS; THALLIUM TELLURIDES; TRICLINIC LATTICES

Citation Formats

Assoud, Abdeljalil, Soheilnia, Navid, and Kleinke, Holger. Crystal structure, electronic structure and physical properties of the new low-valent thallium silicon telluride Tl{sub 6}Si{sub 2}Te{sub 6} in comparison to Tl{sub 6}Ge{sub 2}Te{sub 6}. United States: N. p., 2006. Web. doi:10.1016/j.jssc.2006.05.029.
Assoud, Abdeljalil, Soheilnia, Navid, & Kleinke, Holger. Crystal structure, electronic structure and physical properties of the new low-valent thallium silicon telluride Tl{sub 6}Si{sub 2}Te{sub 6} in comparison to Tl{sub 6}Ge{sub 2}Te{sub 6}. United States. doi:10.1016/j.jssc.2006.05.029.
Assoud, Abdeljalil, Soheilnia, Navid, and Kleinke, Holger. Tue . "Crystal structure, electronic structure and physical properties of the new low-valent thallium silicon telluride Tl{sub 6}Si{sub 2}Te{sub 6} in comparison to Tl{sub 6}Ge{sub 2}Te{sub 6}". United States. doi:10.1016/j.jssc.2006.05.029.
@article{osti_20905427,
title = {Crystal structure, electronic structure and physical properties of the new low-valent thallium silicon telluride Tl{sub 6}Si{sub 2}Te{sub 6} in comparison to Tl{sub 6}Ge{sub 2}Te{sub 6}},
author = {Assoud, Abdeljalil and Soheilnia, Navid and Kleinke, Holger},
abstractNote = {The title compounds were prepared from the elements in the stoichiometric ratio at 800deg. C under exclusion of air. Tl{sub 6}Si{sub 2}Te{sub 6} crystallizes in the space group P1-bar , isostructural with Tl{sub 6}Ge{sub 2}Te{sub 6}, with a=9.4235(6)A, b=9.6606(7)A, c=10.3889(7)A, {alpha}=89.158(2){sup o}, {beta}=96.544(2){sup o}, {gamma}=100.685(2){sup o}, V=923.3(1)A{sup 3} (Z=2). Its structure is composed of dimeric [Si{sub 2}Te{sub 6}]{sup 6-} units with a Si-Si single bond, while the Tl atoms are irregularly coordinated by five to six Te atoms. Numerous weakly bonding Tl-Tl contacts exist. Both title compounds are black semiconductors with small band gaps, calculated to be 0.9eV for Tl{sub 6}Si{sub 2}Te{sub 6} and 0.5eV for Tl{sub 6}Ge{sub 2}Te{sub 6}. The Seebeck coefficients are +65{mu}VK{sup -1} in case of Tl{sub 6}Si{sub 2}Te{sub 6} and +150{mu}VK{sup -1} in case of Tl{sub 6}Ge{sub 2}Te{sub 6} at 300K, and the electrical conductivities are 5.5 and 3{omega}{sup -1}cm{sup -1}, respectively.},
doi = {10.1016/j.jssc.2006.05.029},
journal = {Journal of Solid State Chemistry},
number = 8,
volume = 179,
place = {United States},
year = {Tue Aug 15 00:00:00 EDT 2006},
month = {Tue Aug 15 00:00:00 EDT 2006}
}
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