Tellurides

compounds of tellurium with electropositive elements; salts of hydrotelluric acid, H₂Te. Tellurides are analogues of sulfides and selenides. Alkali metals form with tellurium water-soluble tellurides of the general formula Me₂Te, as well as polytellurides (for example, Na₃Te₂); alkaline-earth metals react with tellurium to form tellurides of the general formula MeTe. Tellurides of transition metals from groups IV-VIII of the periodic system are of variable composition; these compounds are insoluble in water and are decomposed by strong acids.

Tellurides occur in nature in the form of the numerous but extremely rare tellurium minerals. They are synthesized by, for example, the fusion of the components in an inert medium or the reaction of hydrogen telluride with metals or salts of metals. The tellurides of most elements have semiconductor properties. Tellurides are used in manufacturing photocells, infrared detectors, thermoelectric generators, and refrigeration thermoelements; they are also used as high-temperature lubricants. Tellurides of alkali metals are used in processes for producing tellurium.