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Tellurium dioxide

Tellurium dioxide
Other names Tellurium(IV) oxide
Molecular formula TeO2
Molar mass 159.60 g/mol
Appearance White solid
CAS number [7446-07-3]
Density 5.670 g/cm3
Solubility (water) Highly insoluble
Melting point 733 °C
Boiling point 1245 °C
Disclaimer and references

  Tellurium dioxide (TeO2 or paratellurite) is a solid oxide of tellurium. It is used as an acousto-optic material. It forms tetragonal crystals.

Tellurium dioxide is also a conditional glass former, which means it will form a glass with small molar % additions of a second compound such as an oxide or halide. TeO2 glasses have high refractive indices and transmit into the mid-infrared part of the electromagnetic spectrum, therefore they are of technological interest for optical waveguides. Tellurite glasses have also been shown to exhibit Raman gain up to 30 times that of silica, useful in optical fibre amplification.

Chemical properties

TeO2 is the main product of burning tellurium in air. TeO2 is highly insoluble in water and completely insoluble in concentrated sulfuric acid. It is also incompatible with strong acids and strong oxidizing agents. It is an amphoteric substance and therefore can act both as an acid or as a base depending on the solution it is in.

Safety information

TeO2 is a possible teratogen. Harmful, and produces a garlic-like odour on the breath.


K. W. Bagnall, The Chemistry of Selenium, Tellurium and Polonium, pp 59-60, Elsevier, London, 1966.

  • 2005.
This article is licensed under the GNU Free Documentation License. It uses material from the Wikipedia article "Tellurium_dioxide". A list of authors is available in Wikipedia.
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