Tellurogallates are chemical compounds which contain anionic units of tellurium connected to gallium. They can be considered as gallates where tellurium substitutes for oxygen. Similar compounds include the thiogallates, selenogallates, telluroaluminates, telluroindates and thiostannates. They are in the category of chalcogenotrielates or more broadly tellurometallates or chalcogenometallates.
Tellurogallates may be produced by heating a metal with gallium and tellurium in a sealed tube.
Some tellurogallates are semiconductors
Tellurogallates are primarily of research interest. They are investigated for their infrared, thermoelectric and semiconductor characteristics.
name | chem | mw | crystal system | space group | unit cell Å | volume | density | comment | CAS no | references |
---|---|---|---|---|---|---|---|---|---|---|
lithium tellurogallate | LiGaTe2 | 321.86 | tetragonal | I42d | a=6.338 c=11.704 Z=16 | 470.1 | 2.937 | orange to black; band gap 2.41 eV | [1] [2] | |
sodium trigallium pentatelluride | NaGa3Te5 | trigonal | R32 | a=14.58 c=17.761 Z=12 | 3269.5 | 5.272 | black | [3] | ||
[(C6H5)4P]GaTe2(en)2 en = ethane-1,2-diamine | monoclinic | C2/c | a=20.680 b=5.3877 c=27.192 β=19.13° | 3029.6 | 1.720 | orange | [4] | |||
KGaTe2 | monoclinic | C2/c | a=11.768, b=11.775, c=16.503, β=100.36°, Z=16 | [5] | ||||||
KGaTe2 | triclinic | P1 or P1 | a=8.34 b=8.34 c=64.4 αβγ~90° | 4479.4 | 4.30 | [6] | ||||
hexapotassium di-μ-telluridobis (ditelluridogallate) | K6Ga2Te6 | monoclinic | P121/c1 | a = 8.616, b = 13.685, c = 11.290, β = 127.61°, Ζ = 2 | 1054.6 | [7] | ||||
K[K([18]crown-6)]2[GaTe3] · 2CH3CN | monoclinic | C2/m | a=24.469 b=14.073 c=12.875 β=94.47 Z=4 | 4369 | 1.784 | yellow (@113K) | [8] | |||
CaGa6Te10 | monoclinic | C2 | a=14.40 b=14.40 c=10.21 β=90.0 Z=4 | 2117.1 | [9] | |||||
Cr3(GaTe3)2 | amorphous | [10] | ||||||||
MnGa2Te4 | monoclinic | C2/c | a=11.999, b=11.999, c=24.922, β=104.01°, Z=16 | [11] | ||||||
MnGa2Te4 | orthorhombic | Pnma | a = 27.448, b = 4.192, c = 6.993 Z=4 | 804.6 | 5.82 | [12] | ||||
Fe3(GaTe3)2 | amorphous | [10] | ||||||||
Co3(GaTe3)2 | amorphous | [10] | ||||||||
Ni3-xGaTe2 | P63/mmc | a=3.9393 c=15.7933 Z=2 | [13] | |||||||
Ni2FeGaTe | P63/mmc | a=3.962 c=15.868 Z=2 | 215.7 | [13] | ||||||
CuGaTe2 | I42d | a = 6.02348, c = 11.93979 | 433.2 | [14] | ||||||
ZnGa2Te4 | I4 | a=5.930, c=11.859 Z=2 | 5.7 | [15] | ||||||
ZnGa2Te4 | tetragonal | I42m | a=6.922 c=11.809 | [16] | ||||||
ZnGa2Te4 | F43m | a=5.843 Z=1/2 | [16] | |||||||
AgGaTe2 | I42d | a=6.320 c=11.986 Z=2 | 6.052 | melt 725.7°C; heat of fusion= 104.8 J/g−1 | [17] [18] | |||||
AgGa5Te8 | tetragonal | I41/a | a=8.415 c=47.877 | [19] [20] | ||||||
Ag2Ga6Te10 | [19] | |||||||||
Ag9GaTe6 | hexagonal | melt 710°C Low thermal conductivity | [21] [19] [22] | |||||||
CdGa2Te4 | tetragonal | a=5.742 c=10.730 | [23] | |||||||
InGaTe2 | tetragonal | I4/mcm | a = 8.412, c = 6.875; Z = 4; | [24] | ||||||
In2Ga6Te10 | trigonal | R32 | a=10.34 alpha=89.7 Z=12 | 5.78 | [25] | |||||
SnGa6Te10 | trigonal | P3121/6 | a=14.408 c=17.678 Z=6 | 3178 | 5.684 | black | [26] | |||
SnxGa1-xTe x=1/2 | cubic | a=6.315 | 251.84 | [27] | ||||||
β-BaGa2Te4 | orthorhombic | Imma | a = 23.813, b = 11.967, c = 6.7215 | [28] | ||||||
Ba5Ga2Ge3Te12 | monoclinic | P21/c | a = 13.6540, b = 9.6705, and c = 23.1134 β =91.829 | [28] | ||||||
LaGaITe2 | orthorhombic | Pmc21 | [29] | |||||||
CeGaITe2 | orthorhombic | Pmc21 | [29] | |||||||
PrGaITe2 | orthorhombic | Pmc21 | [29] | |||||||
NdGaITe2 | orthorhombic | Pmc21 | [29] | |||||||
Eu0.81Ga2Te4 | tetragonal | I4/mcm | a = 8.2880, c = 6.744, Z = 2 | 463.24 | [30] | |||||
HgGa2Te4 | cubic | F43m | a=6.002 Z=1 | 216.22 | [31] | |||||
HgGa2Te4 | tetragonal | I42m | a=6.025 c=12.037 Z=2 | 436.95 | black | [31] | ||||
TlGaTe2 | tetragonal | I4/mmm D184h | a=8.429 c=6.865 | band gap 0.84 eV | [32] [33] | |||||
Tl2InGaTe4 | tetragonal | I4mcm | [34] | |||||||
PbGa6Te10 | trigonal | P3221/6 | a=14.465 c=17.718 Z=6 | 3210 | 5.898 | black | [35] [26] |
Tellurium is a chemical element; it has symbol Te and atomic number 52. It is a brittle, mildly toxic, rare, silver-white metalloid. Tellurium is chemically related to selenium and sulfur, all three of which are chalcogens. It is occasionally found in its native form as elemental crystals. Tellurium is far more common in the Universe as a whole than on Earth. Its extreme rarity in the Earth's crust, comparable to that of platinum, is due partly to its formation of a volatile hydride that caused tellurium to be lost to space as a gas during the hot nebular formation of Earth.
Zinc telluride is a binary chemical compound with the formula ZnTe. This solid is a semiconductor material with a direct band gap of 2.26 eV. It is usually a p-type semiconductor. Its crystal structure is cubic, like that for sphalerite and diamond.
Lead telluride is a compound of lead and tellurium (PbTe). It crystallizes in the NaCl crystal structure with Pb atoms occupying the cation and Te forming the anionic lattice. It is a narrow gap semiconductor with a band gap of 0.32 eV. It occurs naturally as the mineral altaite.
Mercury telluride (HgTe) is a binary chemical compound of mercury and tellurium. It is a semi-metal related to the II-VI group of semiconductor materials. Alternative names are mercuric telluride and mercury(II) telluride.
Gallium(II) telluride, GaTe, is a chemical compound of gallium and tellurium. There is research interest in the structure and electronic properties of GaTe because of the possibility that it, or related compounds, may have applications in the electronics industry. Gallium telluride can be made by reacting the elements or by metal organic vapour deposition (MOCVD).
The indium chalcogenides include all compounds of indium with the chalcogen elements, oxygen, sulfur, selenium and tellurium. (Polonium is excluded as little is known about its compounds with indium). The best-characterised compounds are the In(III) and In(II) chalcogenides e.g. the sulfides In2S3 and InS.
This group of compounds has attracted a lot of research attention because they include semiconductors, photovoltaics and phase-change materials. In many applications indium chalcogenides are used as the basis of ternary and quaternary compounds such as indium tin oxide, ITO and copper indium gallium selenide, CIGS.
Gallium(II) selenide (GaSe) is a chemical compound. It has a hexagonal layer structure, similar to that of GaS. It is a photoconductor, a second harmonic generation crystal in nonlinear optics, and has been used as a far-infrared conversion material at 14–31 THz and above.
I-III-VI2 semiconductors are solid semiconducting materials that contain three or more chemical elements belonging to groups I, III and VI (IUPAC groups 1/11, 13 and 16) of the periodic table. They usually involve two metals and one chalcogen. Some of these materials have a direct bandgap, Eg, of approximately 1.5 eV, which makes them efficient absorbers of sunlight and thus potential solar cell materials. A fourth element is often added to a I-III-VI2 material to tune the bandgap for maximum solar cell efficiency. A representative example is copper indium gallium selenide (CuInxGa(1–x)Se2, Eg = 1.7–1.0 eV for x = 0–1), which is used in copper indium gallium selenide solar cells.
Molybdenum(IV) telluride, molybdenum ditelluride or just molybdenum telluride is a compound of molybdenum and tellurium with formula MoTe2, corresponding to a mass percentage of 27.32% molybdenum and 72.68% tellurium.
The telluride bromides are chemical compounds that contain both telluride ions (Te2−) and bromide ions (Br−). They are in the class of mixed anion compounds or chalcogenide halides.
The telluride oxides or oxytellurides are double salts that contain both telluride and oxide anions. They are in the class of mixed anion compounds.
The telluride phosphides are a class of mixed anion compounds containing both telluride and phosphide ions. The phosphidotelluride or telluridophosphide compounds have a [TeP]3− group in which the tellurium atom has a bond to the phosphorus atom. A formal charge of −2 is on the phosphorus and −1 on the tellurium. There is no binary compound of tellurium and phosphorus. Not many telluride phosphides are known, but they have been discovered for noble metals, actinides, and group 4 elements.
The telluride iodides are chemical compounds that contain both telluride ions (Te2−) and iodide ions (I−). They are in the class of mixed anion compounds or chalcogenide halides.
Selenogallates are chemical compounds which contain anionic units of selenium connected to gallium. They can be considered as gallates where selenium substitutes for oxygen. Similar compounds include the thiogallates and selenostannates. They are in the category of chalcogenotrielates or more broadly chalcogenometallates.
Gallium palladide is an intermetallic combination of gallium and palladium. It has the iron monosilicide crystal structure. The compound has been suggested as an improved catalyst for hydrogenation reactions. In principle, gallium palladide can be a more selective catalyst since unlike substituted compounds, the palladium atoms are spaced out in a regular crystal structure rather than randomly.
Arsenide bromides or bromide arsenides are compounds containing anions composed of bromide (Br−) and arsenide (As3−). They can be considered as mixed anion compounds. They are in the category of pnictidehalides. Related compounds include the arsenide chlorides, arsenide iodides, phosphide bromides, and antimonide bromides.
Arsenide tellurides or telluride arsenides are compounds containing anions composed of telluride (Te2−) and arsenide (As3−). They can be considered as mixed anion compounds. Related compounds include the arsenide sulfides, arsenide selenides, antimonide tellurides, and phosphide tellurides. Some are in the category of arsenopyrite-type compounds with As:Te of 1:1. Yet others are layered with As:Te of 1:2.
Tellurogermanates or telluridogermanates are compounds with anions with tellurium bound to germanium. They are analogous with germanates, thiogermanates and selenidogermanates.
Aluminium gallium antimonide, also known as gallium aluminium antimonide or AlGaSb (AlxGa1-xSb), is a ternary III-V semiconductor compound. The alloy can contain any ratio between aluminium and gallium; that is, x in the formula can continuously take on any value between 0 and 1. AlGaSb refers generally to any composition of the alloy.