Metal tellurides

Transition-metal tellurides occupy a special place amongst the chalcogenides. In the 

Another interesting example of the special behaviour of tellurides is provided by WTe2 and its relatives(Mar era/., 1992). WS2 and WSc2 crystallize in the layered M0S2 

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However, simple stoichiometry often conceals structural complexity as in the many alkali metal tellurides MTe (jc = 1, 1.5, 2.5, 3,... 

All the dialkali monosulfides are soluble in water and give alkaline solutions. The tellurides are instantly decomposed by air. They are soluble in water, but the solutions are easily oxidized to red polytellurides. The alkali metal tellurides are strong reducing agents which reduce tellurites to metallic tellurium. 

Sheldrick WS, Wachhold M, Jobic S, Brec R, Canadell E (1997) New low-dimensional solids tellurium-rich alkali metal tellurides. Adv Mater 9 669-675 Zheng Zh, Greedan JE (2004) Rare earth elements and materials. In Meyers RA (ed) Encyclopedia of Physical Science and Technology - Inorganic Chemistry. Elsevier Science, URL ... 

Ternary and quaternary metal telluride materials have been prepared from the metallic elements in telluride fluxes, as the compounds CsAgsTe-j, 1 K0.33Ba0.67AgTe2,1052... 

Besides CuInTe2, several other metal tellurides have been deposited using the hydrazine-based approach. Among them, ZnTe is somewhat unique in that the precursor was isolated in single crystal form, and therefore, the structure... 

Despite facile formation of p-type ZnTe from the precursor, films of ZnTe formed from a drop cast precursor solution had a small grain structure (using conditions that we have so far explored), which limited prospective TFT device performance. Note that we expect a similar chemistry to that for ZnTe to also be operative for selected other metal telluride precursors. In contrast to the ZnTe films, well-crystallized films of In2Te3 have been formed using... 

Mitzi, D. B. Copel, M. Murray, C. E. 2006. High-mobihty p-type transistor based on a spin-coated metal telluride semiconductor. Adv. Mater. 18 2448-2452. 

Alkali-metal salts, 24 145 Alkali-metal tellurides, 24 417 Alkali-metal thermal electric conversion (AMTEC), 22 773-774 Alkali-metal titanates, 25 43 44 Alkaline autoclaving, selenium recovery via, 22 81... 

For example, no less than 12 different formula types are now known for the alkali metal tellurides MxTey [9, 10]. As the total bond order for Te-Te bonds and their opposite secondary Te---Te interactions must remain constant at 1.0, distances di/di will increase in logarithmic dependence on their individual bond order as d3/d4 shorten. Values of d-y/di can range from those of typical single bonds (269-287 pm [10]) to 304 + 9 pm for symmetrical and modestly distorted 3-center 4-electron interactions. 

As will be discussed in Section 2.7.3.1, a number of duster-like non-valence precise Te moieties (n = 4, 6) have also been identified in alkali metal tellurides but these alleviate their electron surplus by participating in asymmetric linear 3-... 

Disubstituted tellurins were obtained by reduction (with DIBAL-Fl) of the the 4-oxo-4//-tellurins, prepared by the addition of alkali metal tellurides to... 

In this edition, we have incorporated new material in all the chapters and updated references to the literature. New sections dealing with porous solids, fullerenes and related materials, metal nitrides, metal tellurides, molecular magnets and other organic materials have been added. Under preparative strategies, we have included new types of synthesis reported in the literature, specially those based on soft chemistry routes. We have a new section covering typical results from empirical theory and electron spectroscopy. There is a major section dealing with high-temperature oxide superconductors. We hope that this edition of the book will prove to be a useful text and reference work for all those interested in solid state chemistry and materials science. 

Ultrahigh (99.999 + %) purity tellurium is prepared by zone refining in a hydrogen or inert-gas atmosphere. Single crystals of tellurium, tellurium alloys, and metal tellurides are grown by the Bridgman and Czochralski methods (see Semiconductors). 

Metal tellurides for semiconductors are made by direct melting, melting with excess tellurium and volatilizing the excess under reduced pressure, passing tellurium vapor in an inert gas carrier over a heated metal, and high temperature reduction of oxy compounds with hydrogen or ammonia. 

Electronic and Optoelectronic Applications of Tellurides. Most metal tellurides are semiconductors with a large range of energy gaps and can be used in a variety of electrical and optoelectronic devices. Alloys of the form HgCdTe and PbSnTe have been used as infrared detectors and CdTe has been employed as a gamma, ray detector and is also a promising candidate material for a thin-film solar cell. 

Hydrogen telluride is also obtainable from the metallic tellurides, for example, from magnesium, aluminium, zinc and iron tellurides. These are decomposed by water or by a non-oxidising acid such as dilute... 

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