Antimony telluride
Encyclopedia
Antimony telluride is an inorganic compound
Inorganic compound
Inorganic compounds have traditionally been considered to be of inanimate, non-biological origin. In contrast, organic compounds have an explicit biological origin. However, over the past century, the classification of inorganic vs organic compounds has become less important to scientists,...

 with the chemical formula
Chemical formula
A chemical formula or molecular formula is a way of expressing information about the atoms that constitute a particular chemical compound....

 Sb2Te3. It is a grey, crystalline solid, although its melting point
Melting point
The melting point of a solid is the temperature at which it changes state from solid to liquid. At the melting point the solid and liquid phase exist in equilibrium. The melting point of a substance depends on pressure and is usually specified at standard atmospheric pressure...

, density
Density
The mass density or density of a material is defined as its mass per unit volume. The symbol most often used for density is ρ . In some cases , density is also defined as its weight per unit volume; although, this quantity is more properly called specific weight...

 and colour may depend on the crystalline form
Polymorphism (materials science)
Polymorphism in materials science is the ability of a solid material to exist in more than one form or crystal structure. Polymorphism can potentially be found in any crystalline material including polymers, minerals, and metals, and is related to allotropy, which refers to chemical elements...

 it adopts.

Synthesis

Antimony telluride can be formed by the reaction of antimony
Antimony
Antimony is a toxic chemical element with the symbol Sb and an atomic number of 51. A lustrous grey metalloid, it is found in nature mainly as the sulfide mineral stibnite...

 with tellurium at 500–900 °C.
2Sb(l) + 3Te(l) → Sb2Te3(l)

Applications

Like other binary
Binary compound
A binary compound is a chemical compound that contains exactly two different elements. Examples of binary ionic compounds include calcium chloride , sodium fluoride , and magnesium oxide , whilst examples of binary covalent compounds include water , carbon monoxide , and sulfur hexafluoride...

 chalcogenide
Chalcogenide
A chalcogenide is a chemical compound consisting of at least one chalcogen ion and at least one more electropositive element. Although all group 16 elements of the periodic table are defined as chalcogens, the term is more commonly reserved for sulfides, selenides, and tellurides, rather than...

s of antimony and bismuth
Bismuth
Bismuth is a chemical element with symbol Bi and atomic number 83. Bismuth, a trivalent poor metal, chemically resembles arsenic and antimony. Elemental bismuth may occur naturally uncombined, although its sulfide and oxide form important commercial ores. The free element is 86% as dense as lead...

, Sb2Te3 has been investigated for its semiconductor
Semiconductor
A semiconductor is a material with electrical conductivity due to electron flow intermediate in magnitude between that of a conductor and an insulator. This means a conductivity roughly in the range of 103 to 10−8 siemens per centimeter...

 properties. It can be transformed into both n-type
N-type semiconductor
N-type semiconductors are a type of extrinsic semiconductor where the dopant atoms are capable of providing extra conduction electrons to the host material . This creates an excess of negative electron charge carriers....

 and p-type
P-type semiconductor
A P-type semiconductor is obtained by carrying out a process of doping: that is, adding a certain type of atoms to the semiconductor in order to increase the number of free charge carriers ....

 semiconductors by doping
Doping (semiconductor)
In semiconductor production, doping intentionally introduces impurities into an extremely pure semiconductor for the purpose of modulating its electrical properties. The impurities are dependent upon the type of semiconductor. Lightly and moderately doped semiconductors are referred to as extrinsic...

 with an appropriate dopant
Dopant
A dopant, also called a doping agent, is a trace impurity element that is inserted into a substance in order to alter the electrical properties or the optical properties of the substance. In the case of crystalline substances, the atoms of the dopant very commonly take the place of elements that...

.

Sb2Te3 forms the pseudobinary
Binary compound
A binary compound is a chemical compound that contains exactly two different elements. Examples of binary ionic compounds include calcium chloride , sodium fluoride , and magnesium oxide , whilst examples of binary covalent compounds include water , carbon monoxide , and sulfur hexafluoride...

 intermetallic system germanium-antimony-tellurium
GeSbTe
GeSbTe, Germanium-Antimony-Tellurium or GST is a phase change material from the group of chalcogenide glasses, used in rewritable optical discs and phase-change memory applications. Its recrystallization time is 20 nanoseconds, allowing bitrates of up to 35 Mbit/s to be written, and direct...

 with germanium telluride
Germanium telluride
Germanium telluride is a chemical compound of germanium and tellurium and is a component of chalcogenide glasses. It shows semimetallic conduction and ferroelectric behaviour....

, GeTe.

Like bismuth telluride
Bismuth telluride
Bismuth telluride is a gray powder that is a compound of bismuth and tellurium also known as bismuth telluride. It is a semiconductor which, when alloyed with antimony or selenium is an efficient thermoelectric material for refrigeration or portable power generation...

, Bi2Te3, antimony telluride has a large thermoelectric effect
Thermoelectric cooling
Thermoelectric cooling uses the Peltier effect to create a heat flux between the junction of two different types of materials. A Peltier cooler, heater, or thermoelectric heat pump is a solid-state active heat pump which transfers heat from one side of the device to the other side against the...

 and is therefore used in solid state refrigerators.
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