Tellurium Single Crystal

INTRODUCTION This data sheet presents information information for single crystal tellurium. 

Transmission Region, (External Transmittance 10% with 2. 0 mm. thickness) 3.5 - 8. 0 jl  

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The physical properties of tellurium are generally anistropic. This is so for compressibility, thermal expansion, reflectivity, infrared absorption, and electronic transport. Owing to its weak lateral atomic bonds, crystal imperfections readily occur in single crystals as dislocations and point defects. 

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

Numerous works have been implemented on tellurium electrochemistry and its adsorption at metal surfaces. The morphological structures of electrodeposited Te layers at various stages of deposition (first UPD, second UPD, and bulk deposition) are now well known [88-93]. As discussed in the previous paragraphs, Stickney and co-workers have carried out detailed characterizations of the first Te monolayer on Au single-crystal surfaces in order to establish the method of electrochemical atomic layer epitaxy of CdTe. 

Feliu JM, G6mez R, Llorca MJ, Aldaz A. 1993b. Electrochemical behavior of irreversible adsorbed tellurium dosed from solution on Pt(M/) single crystal electrodes in sulphuric and perchloric acid media. Surf Sci 297 209-222. 

NMR in single-crystal tellurium and selenium also provided information about atomic diffusion [172, 173] as well as the 77Se CSA [174]. 

Te(OH) forms adducts with alkali-metal fluorides such as Te(OH) -NaF or Te(OH)8-2KF (102). Single-crystal X-ray diffraction shows that, contrary to the earlier assumption, there is no direct bonding of fluorine to tellurium. The fluoride ions are incorporated into the structure by short O—H F hydrogen bonds (6, 7). 

Patel et al. °"> successfully operated parametric oscillators in the infrared region (2.5 - 25 pm) using the nonlinear characteristics of tellurium and selenium single crystals. This frequency range is important for the molecular spectroscopy of rotational-vibrational... 

Elemental forms of gallium and arsenic, plus small quantities of dopant material — silicon, tellurium or chromium — are reacted at elevated temperatures to form ingots of doped single-crystal GaAs. 

The tellurium-containing derivatives (for instance, 60) have been obtained and characterized [82-85], Important exceptions are complexes 61, where the Zr = E terminal bond (E = S, Se, Te) is present as proved by x-ray single crystal diffraction studies [88] ... 

Tributylphosphane telluride donated its tellurium atom to decamethylsilicocene to produce dark-red prisms of a heterocyclic compound with two silicon and three tellurium atoms in the ring. The compound was characterized by single-crystal X-ray diffraction2. 

A single-crystal X-ray structural analysis of bis[ethylenethiourea]tellurium dithiocyanate showed the tellurium atom to be coordinated to four sulfur atoms with planar trans-arrangement of the ligands1. 

Single crystal X-ray structural analyses of these compounds3,4 show that the tellurium atom is surrounded by four sulfur atoms from four different dithiophosphate groups in a planar arrangement. The S —P —S group is not a bidentate ligand but serves as a bridge between tellurium atoms. 

Tellurium bis[thiolobenzoate] was obtained from sodium tellurite and thiobenzoic acid in strongly acidic medium. The compound was recrystallized from benzene. A single-crystal X-ray structural analyses showed the thiolobenzoate groups to be bidentate2. 

Tellurium bis[bis(2-hydroxyethyl)dithiocarbamate] and a thirty-fold molar excess of potassium bromide, iodide, or thiocyanate reacted in acetone acidified with acetic acid with replacement of one dithiocarbamate group per two molecules of tellurium dithiocarbamate by halide or thiocyanate. The deep-red crystals are stable as solids but decompose with deposition of tellurium when dissolved in methanol. The single-crystal X-ray structural analysis of the thiocyanato derivative revealed the presence of two chemically different tellurium atoms in the molecule that are in short contact1. 

When tellurium tetrachloride was condensed with A,A,jV -tris[trimethylsilyl]benzamidine in dry dichloromethane, N,N -bis[trimethylsilyl benzamidinyl tellurium trichloride was isolated in the form of white crystals that were characterized by single-crystal X-ray diffraction3. The tellurium atom is surrounded by three chlorine and two nitrogen atoms in the monomeric molecule. 

A single-crystal X-ray structural investigation of 2-(phenylazo)phenyl tellurium thiocyanate revealed the thiocyanato group to be bonded to the tellurium atom via the sulfur atom4. 

The single crystal X-ray structural analysis of bis[diphenyl thiocyanato] tellurium oxide showed that the two tellurium atoms in the molecule are linked by an oxygen atom. The thiocyanate groups are bonded to tellurium via the nitrogen atoms1. 

All compounds were characterized by, 9F- and 125Te-NMR spectroscopy and triphenyltrifluoro tellurium by single-crystal X-ray diffraction4. 

Cyanide has the possibility of bonding to tellurium via the C atom or the N atom. The v(CN) absorption for nitriles, R-CN, occurs at 2260-2220 cm-1, and for isonitriles, R-NC, at 2160-2120 cm-1. However, the single crystal X-ray structural analysis of 4-nitrobenzyl tellurium cyanide showed that the cyanide group is bonded to the tellurium atom via the carbon atom1. Thus, di- and triorgano tellurium cyanides are discussed here. 

Most of the diorgano alkylidene tellurium compounds thus far reported derive their alkylidene group from 5,5-dimethyl-l,3-dioxocyclohexane. These diorgano cyclohexyl-idene tellurium compounds are colorless, crystalline substances that are stable at 20° and readily soluble in benzene, carbon tetrachloride, and dichloromethane2,3. Single crystal X-ray diffraction showed that the tellurium atom in bis[4-methoxyphenyl] 5,5-dimethyl-l,3-dioxo-2,2-cyclohexylidene tellurium occupies the apex of a trigonal pyramid4. 

Tellurium is a p-type semiconductor. The element shows anisotropy in electrical conductivity that is essentially independent of temperature in the range 78-200 K. It has been reported that single crystals grown in vapor show more strongly metallic conductivity parallel to the Te chains. The conductivity of tellurium is much less affected by illumination than that of selenium. 

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