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Formation and Properties of Some Subhalides of Tellurium

  • A. Rabenau

Abstract

Subhalides of tellurium with the general formula Tey X (X = Cl, Br, I; y≥1) show unusual properties. From the six examples of this new group of compounds:\( T{e_3}C{l_2}^\aleph ,T{e_2}Cl,T{e_2}B{r^\aleph },T{e_2}I,\beta - TeI,\alpha - Te{I^\aleph } \) only those with an asterisk are thermodynamically stable crystalline phases with respect to the appropriate phase diagrams TeTeX4, which form pseudobinary peritectic systems. In spite of the thermodynamic facts, all compounds can be obtained as crystalline solids. The “ unsaturation ” with respect to tellurium is reflected in the crystal structures of the subhalides, whose main characteristic is bonding in various geometries between tellurium atoms (1). The structural unit of elemental tellurium — a screw with 31 or 32 symmetry — is stepwise modified to a series of other infinite arrangements and finally to a molecular type structure (α-TeI) Fig. 1. Even in the latter case, the Te4I4 molecules form chains parallel to the c-axes. The strong relationship of the molecular type to the chain structures is demonstrated by the topotactical transformation of a small single crystal of ß-TeI into a crystal of the stable form α-TeI.

Keywords

Thermodynamic Fact Tellurium Atom Solid State Comm Tellurium Content Elemental Tellurium 
These keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.

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References

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    U. von Alpen, J. Haag, and A. Rabenau, Mat.Res. Bull. 11,7 (1976)CrossRefGoogle Scholar

Copyright information

© Springer Science+Business Media New York 1977

Authors and Affiliations

  • A. Rabenau
    • 1
  1. 1.Max-Planck-Institut für FestkörperforschungStuttgartGermany

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