Characteristics of the chemical element germanium. germanium element

Germanium |32 | Ge| — Price

Germanium (Ge) - trace rare metal, atomic number - 32, atomic mass-72.6, density:
solid at 25°C - 5.323 g/cm3;
liquid at 100°C - 5.557g/cm3;
Melting point - 958.5 ° C, coefficient of linear expansion α.106, at temperature, KO:
273-573— 6.1
573-923— 6.6
Hardness on a mineralogical scale-6-6.5.
Electrical resistivity of single-crystal high-purity germanium (at 298 OK), Ohm.m-0.55-0.6 ..
Germanium was discovered in 1885 and was initially obtained as a sulfide. This metal was predicted by D.I. Mendeleev in 1871, with an exact indication of its properties, and he called it ecosilicium. Germanium is named by scientific researchers after the country in which it was discovered.
Germanium is a silvery white metal, on appearance similar to tin, brittle normal conditions. Amenable to plastic deformation at temperatures above 550°C. Germanium has semiconductor properties. The electrical resistivity of germanium depends on the purity—impurities sharply reduce it. Germanium is optically transparent in the infrared region of the spectrum, has a high refractive index, which allows it to be used for the manufacture of various optical systems.
Germanium is stable in air at temperatures up to 700°C, at higher temperatures it oxidizes, and above the melting point it burns to form germanium dioxide. Hydrogen does not interact with germanium, and at the melting point, the germanium melt absorbs oxygen. Germanium does not react with nitrogen. With chlorine, forms at room temperature, germanium chloride.
Germanium does not interact with carbon, is stable in water, slowly interacts with acids, and easily dissolves in aqua regia. Alkali solutions have little effect on germanium. Germanium alloys with all metals.
Despite the fact that germanium is larger in nature than lead, its production is limited due to its strong dispersal in the earth's crust, and the cost of germanium is quite high. Germanium forms the minerals argyrodite and germanite, but they are little used to obtain it. Germanium is extracted along the way during the processing of polymetallic sulfide ores, some iron ores, which contain up to 0.001% germanium, from tar water during coal coking.

RECEIVING.

Obtaining germanium from various raw materials is carried out by complex methods, in which the final product is germanium tetrachloride or germanium dioxide, from which metallic germanium is obtained. It is purified and, further, germanium single crystals with desired electrophysical properties are grown by the method of zone melting. In industry, single-crystal and polycrystalline germanium are obtained.
Semi-products obtained by processing minerals contain a small amount of germanium and various methods of pyro- and hydrometallurgical processing are used for their enrichment. Pyrometallurgical methods are based on the sublimation of volatile compounds containing germanium, hydrometallurgical methods are based on the selective dissolution of germanium compounds.
To obtain germanium concentrates, products of pyrometallurgical enrichment (sublimes, cinders) are treated with acids and germanium is transferred into a solution, from which a concentrate is obtained by various methods (precipitation, co-precipitation and sorption, electrochemical methods). The concentrate contains from 2 to 20% germanium, from which pure germanium dioxide is isolated. Germanium dioxide is reduced with hydrogen, however, the resulting metal is not pure enough for semiconductor devices and therefore it is purified by crystallographic methods (directed crystallization-zone purification-obtaining a single crystal). Directional crystallization is combined with the reduction of germanium dioxide with hydrogen. The molten metal is gradually pushed out of the hot zone into the refrigerator. The metal crystallizes gradually along the length of the ingot. Impurities are collected in the final part of the ingot and removed. The remaining ingot is cut into pieces, which are loaded into zone cleaning.
As a result of zone cleaning, an ingot is obtained, in which the purity of the metal is different along its length. The ingot is also cut and its individual parts are removed from the process. Thus, when obtaining single-crystal germanium from zone-cleaned, the direct yield is no more than 25%.
To obtain semiconductor devices, a single crystal of germanium is cut into plates, from which miniature parts are cut out, which are then ground and polished. These parts are the final product for the creation of semiconductor devices.

APPLICATION.

• Due to its semiconductor properties, germanium is widely used in radio electronics for the manufacture of crystalline rectifiers (diodes) and crystalline amplifiers (triodes), for computer technology, remote control, radar, etc.

• Germanium triodes are used to amplify, generate and convert electrical oscillations.

• In radio engineering, germanium film resistances are used.

• Germanium is used in photodiodes and photoresistors, for the manufacture of thermistors.

• In nuclear technology, germanium gamma-ray detectors are used, and in infrared technology devices, germanium lenses doped with gold are used.

• Germanium is added to alloys for highly sensitive thermocouples.

• Germanium is used as a catalyst in the production of artificial fibers.

• In medicine, some germanium organic compounds are being studied, suggesting that they can be biologically active and help delay the development of malignant tumors, lower blood pressure, and relieve pain.

Germanium(lat. Germanium), Ge, a chemical element of group IV periodic system Mendeleev; serial number 32, atomic mass 72.59; gray-white solid with a metallic luster. Natural Germanium is a mixture of five stable isotopes with mass numbers 70, 72, 73, 74 and 76. The existence and properties of Germany were predicted in 1871 by D. I. Mendeleev and called this still unknown element ekasilicium due to the similarity of its properties with silicon. In 1886, the German chemist K. Winkler discovered a new element in the mineral argyrodite, which he named Germany in honor of his country; Germanium turned out to be quite identical to ecasilience. Until the second half of the 20th century practical use Germany remained very limited. industrial production Germany arose in connection with the development of semiconductor electronics.

The total content of Germanium in the earth's crust is 7·10 -4% by mass, that is, more than, for example, antimony, silver, bismuth. However, Germany's own minerals are extremely rare. Almost all of them are sulfosalts: germanite Cu 2 (Cu, Fe, Ge, Zn) 2 (S, As) 4, argyrodite Ag 8 GeS 6, confieldite Ag 8 (Sn, Ge)S 6 and others. The bulk of Germany is scattered in the earth's crust in large numbers. rocks and minerals: in sulfide ores of non-ferrous metals, in iron ores, in some oxide minerals (chromite, magnetite, rutile and others), in granites, diabases and basalts. In addition, germanium is present in almost all silicates, in some deposits hard coal and oil.

Physical properties Germany. Germanium crystallizes in a diamond-type cubic structure, unit cell parameter a = 5.6575Å. The density of solid Germanium is 5.327 g/cm 3 (25°C); liquid 5.557 (1000°C); t pl 937.5°C; bp about 2700°C; thermal conductivity coefficient ~60 W/(m K), or 0.14 cal/(cm sec deg) at 25°C. Even very pure germanium is brittle at ordinary temperatures, but above 550°C it lends itself to plastic deformation. Hardness Germany on a mineralogical scale 6-6,5; compressibility coefficient (in the pressure range 0-120 Gn/m 2 , or 0-12000 kgf/mm 2) 1.4 10 -7 m 2 /mn (1.4 10 -6 cm 2 /kgf); surface tension 0.6 N/m (600 dynes/cm). Germanium is a typical semiconductor with a band gap of 1.104 10 -19 J or 0.69 eV (25°C); electrical resistivity high purity Germany 0.60 ohm-m (60 ohm-cm) at 25°C; the mobility of electrons is 3900 and the mobility of holes is 1900 cm 2 /v sec (25 ° C) (with an impurity content of less than 10 -8%). Transparent to infrared rays with a wavelength greater than 2 microns.

Chemical properties Germany. In chemical compounds, germanium usually exhibits valences of 2 and 4, with compounds of 4-valent germanium being more stable. At room temperature, germanium is resistant to air, water, alkali solutions, and dilute hydrochloric and sulfuric acids, but is easily soluble in aqua regia and in an alkaline solution of hydrogen peroxide. Nitric acid slowly oxidizes. When heated in air to 500-700°C, germanium is oxidized to GeO and GeO 2 oxides. Germany oxide (IV) - white powder with t pl 1116°C; solubility in water 4.3 g/l (20°C). According to its chemical properties, it is amphoteric, soluble in alkalis and with difficulty in mineral acids. It is obtained by calcining the hydrated precipitate (GeO 3 nH 2 O) released during the hydrolysis of GeCl 4 tetrachloride. By fusing GeO 2 with other oxides, derivatives of germanic acid can be obtained - metal germanates (Li 2 GeO 3, Na 2 GeO 3 and others) - solids with high temperatures melting.

When germanium reacts with halogens, the corresponding tetrahalides are formed. The reaction proceeds most easily with fluorine and chlorine (already at room temperature), then with bromine (weak heating) and iodine (at 700-800°C in the presence of CO). One of the most important compounds Germany GeCl 4 tetrachloride is a colorless liquid; t pl -49.5°C; bp 83.1°C; density 1.84 g/cm 3 (20°C). Water strongly hydrolyzes with the release of a precipitate of hydrated oxide (IV). It is obtained by chlorination of metallic Germany or by the interaction of GeO 2 with concentrated HCl. Also known are Germany dihalides of the general formula GeX 2 , GeCl monochloride, Ge 2 Cl 6 hexachlorodigermane, and Germany oxychlorides (for example, CeOCl 2).

Sulfur reacts vigorously with Germany at 900-1000°C to form GeS 2 disulfide, a white solid, mp 825°C. GeS monosulfide and similar compounds of Germany with selenium and tellurium, which are semiconductors, are also described. Hydrogen slightly reacts with germanium at 1000-1100°C to form germine (GeH) X, an unstable and easily volatile compound. By reacting germanides with dilute hydrochloric acid, germanohydrogens of the series Ge n H 2n+2 up to Ge 9 H 20 can be obtained. Germylene composition GeH 2 is also known. Germanium does not directly react with nitrogen, however, there is Ge 3 N 4 nitride, which is obtained by the action of ammonia on Germanium at 700-800°C. Germanium does not interact with carbon. Germanium forms compounds with many metals - germanides.

Numerous complex compounds of germany are known, which are becoming increasingly important both in the analytical chemistry of germanium and in the processes of its preparation. Germanium forms complex compounds with organic hydroxyl-containing molecules (polyhydric alcohols, polybasic acids, and others). Heteropolyacids Germany were obtained. As well as for other elements of group IV, Germany is characterized by the formation of organometallic compounds, an example of which is tetraethylgermane (C 2 H 5) 4 Ge 3.

Getting Germany. In industrial practice, germanium is obtained mainly from by-products of the processing of non-ferrous metal ores (zinc blende, zinc-copper-lead polymetallic concentrates) containing 0.001-0.1% Germany. Ash from coal combustion, dust from gas generators and waste from coke plants are also used as raw materials. Originally from listed sources different ways, depending on the composition of the raw material, receive a germanium concentrate (2-10% Germany). The extraction of Germany from a concentrate usually includes the following stages: 1) chlorination of the concentrate with hydrochloric acid, its mixture with chlorine in aquatic environment or other chlorinating agents to obtain technical GeCl 4 . To purify GeCl 4, rectification and extraction of impurities with concentrated HCl are used. 2) Hydrolysis of GeCl 4 and calcination of hydrolysis products to obtain GeO 2 . 3) Reduction of GeO 2 with hydrogen or ammonia to metal. To isolate very pure germanium, which is used in semiconductor devices, metal is melted by zone. Single-crystal germanium, necessary for the semiconductor industry, is usually obtained by zone melting or by the Czochralski method.

Application Germany. Germanium is one of the most valuable materials in modern semiconductor technology. It is used to make diodes, triodes, crystal detectors, and power rectifiers. Single-crystal germanium is also used in dosimetric instruments and instruments that measure the intensity of constant and alternating magnetic fields. An important field of application in Germany is infrared technology, in particular the production of detectors infrared radiation working in the area of ​​8-14 microns. Many alloys containing germanium, glasses based on GeO2, and other germanium compounds are promising for practical use.

The chemical element germanium is in the fourth group (main subgroup) in the periodic table of elements. It belongs to the family of metals, its relative atomic mass is 73. By mass, the content of germanium in the earth's crust is estimated at 0.00007 percent by mass.

Discovery history

The chemical element germanium was established thanks to the predictions of Dmitry Ivanovich Mendeleev. It was he who predicted the existence of ecasilicon, and recommendations were given for its search.

He believed that this metal element is found in titanium, zirconium ores. Mendeleev tried on his own to find this chemical element, but his attempts were unsuccessful. Only fifteen years later, at a mine located in Himmelfurst, a mineral was found, called argyrodite. To your name this compound due to the silver found in this mineral.

The chemical element germanium in the composition was discovered only after a group of chemists from the Freiberg Mining Academy began research. Under the guidance of K. Winkler, they found out that only 93 percent of the mineral is accounted for by oxides of zinc, iron, as well as sulfur, mercury. Winkler suggested that the remaining seven percent came from a chemical element unknown at the time. After additional chemical experiments, germanium was discovered. The chemist announced his discovery in a report, presented the information received on the properties of the new element to the German Chemical Society.

The chemical element germanium was introduced by Winkler as a non-metal, by analogy with antimony and arsenic. The chemist wanted to call it neptunium, but that name had already been used. Then it began to be called germanium. The chemical element discovered by Winkler caused a serious discussion among the leading chemists of the time. The German scientist Richter suggested that this is the same exasilicon that Mendeleev spoke of. Some time later, this assumption was confirmed, which proved the viability of the periodic law created by the great Russian chemist.

Physical properties

How can germanium be characterized? The chemical element has 32 serial number in Mendeleev. This metal melts at 937.4 °C. The boiling point of this substance is 2700 °C.

Germanium is an element that was first used in Japan for medical purposes. After numerous studies of organogermanium compounds carried out on animals, as well as in the course of studies on humans, it was possible to find a positive effect of such ores on living organisms. In 1967, Dr. K. Asai succeeded in discovering the fact that organic germanium has a huge spectrum of biological effects.

Biological activity

What is the characteristic chemical element Germany? It is able to carry oxygen to all tissues of a living organism. Once in the blood, it behaves by analogy with hemoglobin. Germanium guarantees the full functioning of all systems of the human body.

It is this metal that stimulates the reproduction of immune cells. It, in the form of organic compounds, allows the formation of gamma-interferons, which inhibit the reproduction of microbes.

Germanium interferes with the formation malignant tumors prevents the development of metastases. Organic compounds of this chemical element contribute to the production of interferon, a protective protein molecule that is produced by the body as a protective reaction to the appearance of foreign bodies.

Areas of use

The antifungal, antibacterial, antiviral property of germanium has become the basis for its areas of application. In Germany, this element was mainly obtained as a by-product of the processing of non-ferrous ores. Different ways, which depend on the composition of the feedstock, germanium concentrate was isolated. It contained no more than 10 percent of the metal.

How exactly in semiconductor modern technology is germanium used? The characteristic of the element given earlier confirms the possibility of its use for the production of triodes, diodes, power rectifiers, and crystal detectors. Germanium is also used in the creation of dosimetric instruments, devices that are necessary to measure the strength of a constant and alternating magnetic field.

An essential area of ​​application of this metal is the manufacture of infrared radiation detectors.

It is promising to use not only germanium itself, but also some of its compounds.

Chemical properties

Germanium at room temperature is quite resistant to moisture and atmospheric oxygen.

In the series - germanium - tin), an increase in the reducing ability is observed.

Germanium is resistant to solutions of hydrochloric and sulfuric acids, it does not interact with alkali solutions. At the same time, this metal dissolves rather quickly in aqua regia (seven nitric and hydrochloric acids), as well as in an alkaline solution of hydrogen peroxide.

How to give complete description chemical element? Germanium and its alloys must be analyzed not only by physical, chemical properties but also to areas of application. The process of oxidation of germanium with nitric acid proceeds rather slowly.

Being in nature

Let's try to characterize the chemical element. Germanium is found in nature only in the form of compounds. Among the most common germanium-containing minerals in nature, we single out germanite and argyrodite. In addition, germanium is present in zinc sulfides and silicates, and in small amounts in various types of coal.

Harm to health

What effect does germanium have on the body? A chemical element whose electronic formula is 1e; 8 e; 18 e; 7 e, can adversely affect the human body. For example, when loading a germanium concentrate, grinding, as well as loading the dioxide of this metal, occupational diseases may appear. As other sources that are harmful to health, we can consider the process of remelting germanium powder into bars, obtaining carbon monoxide.

Adsorbed germanium can be quickly excreted from the body, mostly with urine. There is currently no detailed information on how toxic inorganic compounds Germany.

Germanium tetrachloride has an irritating effect on the skin. In clinical trials, as well as with long-term oral administration of cumulative amounts that reached 16 grams of spirogermanium (an organic antitumor drug), as well as other germanium compounds, nephrotoxic and neurotoxic activity of this metal was found.

Such dosages are generally not typical for industrial enterprises. Those experiments that were carried out on animals were aimed at studying the effect of germanium and its compounds on a living organism. As a result, it was possible to establish a deterioration in health when inhaling a significant amount of dust of metallic germanium, as well as its dioxide.

Scientists have found serious morphological changes in the lungs of animals, which are similar to proliferative processes. For example, a significant thickening of the alveolar sections was revealed, as well as hyperplasia of the lymphatic vessels around the bronchi, thickening of the blood vessels.

Germanium dioxide does not irritate the skin, but direct contact of this compound with the membrane of the eye leads to the formation of germanic acid, which is a serious ocular irritant. With prolonged intraperitoneal injections, serious changes in peripheral blood were found.

Important Facts

The most harmful germanium compounds are germanium chloride and germanium hydride. The latter substance provokes serious poisoning. As a result of a morphological examination of the organs of animals that died during the acute phase, they showed significant disorders in the circulatory system, as well as cellular modifications in the parenchymal organs. Scientists have concluded that hydride is a multipurpose poison that affects nervous system, depresses the peripheral circulatory system.

germanium tetrachloride

He is a strong irritant respiratory system, eyes, skin. At a concentration of 13 mg/m 3 it is able to suppress the pulmonary response at the cellular level. With increasing concentration given substance there is severe irritation of the upper respiratory tract, significant changes in the rhythm and frequency of breathing.

Poisoning with this substance leads to catarrhal-desquamative bronchitis, interstitial pneumonia.

Receipt

Since in nature germanium is present as an impurity to nickel, polymetallic, tungsten ores, several labor-intensive processes associated with ore enrichment are carried out in industry to isolate pure metal. First, germanium oxide is isolated from it, then it is reduced with hydrogen at an elevated temperature to obtain a simple metal:

GeO2 + 2H2 = Ge + 2H2O.

Electronic properties and isotopes

Germanium is considered an indirect-gap typical semiconductor. The value of its permittivity is 16, and the value of electron affinity is 4 eV.

In a thin film doped with gallium, it is possible to give germanium a state of superconductivity.

There are five isotopes of this metal in nature. Of these, four are stable, and the fifth undergoes double beta decay, the half-life is 1.58×10 21 years.

Conclusion

Currently, organic compounds of this metal are used in various industries. Transparency in the infrared spectral region of metallic ultra-high purity germanium is important for the manufacture of optical elements of infrared optics: prisms, lenses, optical windows of modern sensors. The most common area of ​​use of germanium is the creation of optics for thermal imaging cameras that operate in the wavelength range from 8 to 14 microns.

Similar devices are used in military equipment for infrared guidance systems, night vision, passive thermal imaging, fire protection systems. Also, germanium has a high refractive index, which is necessary for anti-reflective coating.

In radio engineering, germanium-based transistors have characteristics that, in many respects, exceed those of silicon elements. The reverse currents of germanium cells are significantly higher than those of their silicon counterparts, which makes it possible to significantly increase the efficiency of such radio devices. Given that germanium is not as common in nature as silicon, silicon semiconductor elements are mainly used in radio devices.

Germanium

GERMANIUM-I; m. Chemical element (Ge), a grayish-white solid with a metallic luster (is the main semiconductor material). Germanium plate.

◁ Germanium, th, th. G-th raw material. G. ingot.

(lat. Germanium), a chemical element of group IV of the periodic system. The name from the Latin Germania - Germany, in honor of the homeland of K. A. Winkler. Silver gray crystals; density 5.33 g / cm 3, t pl 938.3ºC. Dispersed in nature (own minerals are rare); mined from ores of non-ferrous metals. Semiconductor material for electronic devices (diodes, transistors, etc.), alloy component, material for lenses in IR devices, ionizing radiation detectors.

GERMANIUM (lat. Germanium), Ge (read "hertempmanium"), a chemical element with atomic number 32, atomic mass 72.61. Natural germanium consists of five isotopes with mass numbers 70 (the content in the natural mixture is 20.51% by mass), 72 (27.43%), 73 (7.76%), 74 (36.54%), and 76 ( 7.76%). Outer electron layer configuration 4 s 2 p 2 . Oxidation states +4, +2 (valencies IV, II). It is located in the IVA group, in the 4th period in the Periodic Table of the Elements.
Discovery history
Was discovered by K. A. Winkler (cm. WINKLER Klemens Alexander)(and named after his homeland - Germany) in 1886 when analyzing the mineral argyrodite Ag 8 GeS 6 after the existence of this element and some of its properties were predicted by D. I. Mendeleev (cm. MENDELEEV Dmitry Ivanovich).
Being in nature
The content in the earth's crust is 1.5 10 -4% by weight. Refers to scattered elements. In nature in free form does not occur. Contained as an impurity in silicates, sedimentary iron, polymetallic, nickel and tungsten ores, coals, peat, oils, thermal waters and algae. The most important minerals: germanite Cu 3 (Ge, Fe, Ga) (S, As) 4, stottite FeGe (OH) 6, plumbogermanite (Pb, Ge, Ga) 2 SO 4 (OH) 2 2H 2 O, argyrodite Ag 8 GeS 6 , rhenierite Cu 3 (Fe, Ge, Zn) (S, As) 4 .
Getting germanium
To obtain germanium, by-products of the processing of non-ferrous metal ores, ash from coal combustion, and some by-products of coke chemistry are used. Feedstock containing Ge is enriched by flotation. Then the concentrate is converted into GeO 2 oxide, which is reduced with hydrogen (cm. HYDROGEN):
GeO 2 + 4H 2 \u003d Ge + 2H 2 O
Semiconductor purity germanium with an impurity content of 10 -3 -10 -4% is obtained by zone melting (cm. ZONE MELTING), crystallization (cm. CRYSTALLIZATION) or thermolysis of volatile monogermane GeH 4:
GeH 4 \u003d Ge + 2H 2,
which is formed during the decomposition of compounds with acids active metals with Ge - germanides:
Mg 2 Ge + 4HCl \u003d GeH 4 - + 2MgCl 2
Physical and chemical properties
Germanium is a silvery substance with a metallic luster. Crystal cell stable modification (Ge I), cubic, face-centered diamond type, a= 0.533 nm (at high pressures three other modifications were obtained). Melting point 938.25 ° C, boiling point 2850 ° C, density 5.33 kg / dm 3. It has semiconductor properties, the band gap is 0.66 eV (at 300 K). Germanium is transparent to infrared radiation with a wavelength greater than 2 microns.
The chemical properties of Ge are similar to those of silicon. (cm. SILICON). At normal conditions resistant to oxygen (cm. OXYGEN), water vapor, dilute acids. In the presence of strong complexing agents or oxidizing agents, when heated, Ge reacts with acids:
Ge + H 2 SO 4 conc \u003d Ge (SO 4) 2 + 2SO 2 + 4H 2 O,
Ge + 6HF \u003d H 2 + 2H 2,
Ge + 4HNO 3 conc. \u003d H 2 GeO 3 + 4NO 2 + 2H 2 O
Ge reacts with aqua regia (cm. AQUA REGIA):
Ge + 4HNO 3 + 12HCl = GeCl 4 + 4NO + 8H 2 O.
Ge interacts with alkali solutions in the presence of oxidizing agents:
Ge + 2NaOH + 2H 2 O 2 \u003d Na 2.
When heated in air to 700 °C, Ge ignites. Ge easily interacts with halogens (cm. HALOGENS) and gray (cm. SULFUR):
Ge + 2I 2 = GeI 4
With hydrogen (cm. HYDROGEN), nitrogen (cm. NITROGEN), carbon (cm. CARBON) germanium does not directly enter into the reaction; compounds with these elements are obtained indirectly. For example, Ge 3 N 4 nitride is formed by dissolving germanium diiodide GeI 2 in liquid ammonia:
GeI 2 + NH 3 liquid -> n -> Ge 3 N 4
Germanium oxide (IV), GeO 2, - white crystalline substance, which exists in two versions. One of the modifications is partially soluble in water with the formation of complex germanic acids. Shows amphoteric properties.
GeO 2 interacts with alkalis as an acid oxide:
GeO 2 + 2NaOH \u003d Na 2 GeO 3 + H 2 O
GeO 2 interacts with acids:
GeO 2 + 4HCl \u003d GeCl 4 + 2H 2 O
Ge tetrahalides are non-polar compounds that are easily hydrolyzed by water.
3GeF 4 + 2H 2 O \u003d GeO 2 + 2H 2 GeF 6
Tetrahalides are obtained by direct interaction:
Ge + 2Cl 2 = GeCl 4
or thermal decomposition:
BaGeF6 = GeF4 + BaF2
Germanium hydrides are chemically similar to silicon hydrides, but GeH 4 monogermane is more stable than SiH 4 monosilane. Germanes form homologous series Ge n H 2n+2 , Ge n H 2n and others, but these series are shorter than those of silanes.
Monogermane GeH 4 is a gas that is stable in air and does not react with water. During long-term storage, it decomposes into H 2 and Ge. Monogermane is obtained by reduction of germanium dioxide GeO 2 with sodium borohydride NaBH 4:
GeO 2 + NaBH 4 \u003d GeH 4 + NaBO 2.
The very unstable GeO monoxide is formed by moderate heating of a mixture of germanium and GeO 2 dioxide:
Ge + GeO 2 = 2GeO.
Ge(II) compounds easily disproportionate with the release of Ge:
2GeCl 2 -> Ge + GeCl 4
Germanium disulfide GeS 2 is a white amorphous or crystalline substance, obtained by precipitation of H 2 S from acidic solutions of GeCl 4:
GeCl 4 + 2H 2 S \u003d GeS 2 Ї + 4HCl
GeS 2 dissolves in alkalis and ammonium or alkali metal sulfides:
GeS 2 + 6NaOH \u003d Na 2 + 2Na 2 S,
GeS 2 + (NH 4) 2 S \u003d (NH 4) 2 GeS 3
Ge can be a part of organic compounds. Known are (CH 3) 4 Ge, (C 6 H 5) 4 Ge, (CH 3) 3 GeBr, (C 2 H 5) 3 GeOH and others.
Application
Germanium is a semiconductor material used in engineering and radio electronics in the production of transistors and microcircuits. Thin films of Ge deposited on glass are used as resistances in radar installations. Alloys of Ge with metals are used in sensors and detectors. Germanium dioxide is used in the production of glasses that transmit infrared radiation.

encyclopedic Dictionary . 2009 .

See what "germanium" is in other dictionaries:

A chemical element discovered in 1886 in the rare mineral argyrodite found in Saxony. Dictionary foreign words included in the Russian language. Chudinov A.N., 1910. germanium (named in honor of the motherland of the scientist who discovered the element), chem. element, ... ... Dictionary of foreign words of the Russian language

- (Germanium), Ge, a chemical element of group IV of the periodic system, atomic number 32, atomic mass 72.59; non-metal; semiconductor material. Germanium was discovered by the German chemist K. Winkler in 1886 ... Modern Encyclopedia

germanium- Ge Group IV element systems; at. n. 32, at. m. 72.59; tv. thing in with metallic. glitter. Natural Ge is a mixture of five stable isotopes with mass numbers 70, 72, 73, 74 and 76. The existence and properties of Ge were predicted in 1871 by D. I. ... ... Technical Translator's Handbook

Germanium- (Germanium), Ge, a chemical element of group IV of the periodic system, atomic number 32, atomic mass 72.59; non-metal; semiconductor material. Germanium was discovered by the German chemist K. Winkler in 1886. ... Illustrated Encyclopedic Dictionary

- (lat. Germanium) Ge, a chemical element of group IV of the periodic system, atomic number 32, atomic mass 72.59. Named from the Latin Germania Germany, in honor of the homeland of K. A. Winkler. Silver gray crystals; density 5.33 g/cm³, mp 938.3 ... Big Encyclopedic Dictionary

- (symbol Ge), white-gray metal element of group IV periodic table MENDELEEV, in which the properties were not yet predicted. open elements, in particular germanium (1871). The element was discovered in 1886. A by-product of zinc smelting ... ... Scientific and technical encyclopedic dictionary

Ge (from lat. Germania Germany * a. germanium; n. Germanium; f. germanium; and. germanio), chem. element IV group periodic. systems of Mendeleev, at.s. 32, at. m. 72.59. Natural G. consists of 4 stable isotopes 70Ge (20.55%), 72Ge ... ... Geological Encyclopedia

- (Ge), synthetic single crystal, PP, point symmetry group m3m, density 5.327 g/cm3, Tmelt=936 °C, solid. on the Mohs scale 6, at. m. 72.60. Transparent in the IR region l from 1.5 to 20 microns; optically anisotropic, for l=1.80 µm eff. refraction n=4.143.… … Physical Encyclopedia

Exist., number of synonyms: 3 semiconductor (7) ecasilicon (1) element (159) ... Synonym dictionary

GERMANIUM- chem. element, symbol Ge (lat. Germanium), at. n. 32, at. m. 72.59; brittle silvery gray crystalline substance, density 5327 kg/m3, vil = 937.5°C. Dispersed in nature; it is mined mainly during the processing of zinc blende and ... ... Great Polytechnic Encyclopedia

Germanium(lat. germanium), ge, a chemical element of group iv of Mendeleev's periodic system; serial number 32, atomic mass 72.59; gray-white solid with a metallic luster. Natural hydrogen is a mixture of five stable isotopes with mass numbers 70, 72, 73, 74, and 76. The existence and properties of hydrogen were predicted in 1871 by D.I. with silicon. In 1886, the German chemist C. Winkler discovered a new element in the mineral argyrodite, which he named G. in honor of his country; G. turned out to be quite identical to "ecasilience". Until the 2nd half of the 20th century. G.'s practical application remained very limited. The industrial production of G. arose in connection with the development of semiconductor electronics.

The total content of G. in the earth's crust 7 . 10 -4% by weight, i.e. more than, for example, antimony, silver, bismuth. However, G.'s own minerals are extremely rare. Almost all of them are sulfosalts: germanite cu 2 (cu, fe, ge, zn) 2 (s, as) 4, argyrodite ag 8 ges 6, confieldite ag 8 (sn, ce) s 6, etc. The bulk of G. dispersed in the earth's crust in a large number of rocks and minerals: in sulfide ores of non-ferrous metals, in iron ores, in some oxide minerals (chromite, magnetite, rutile, etc.), in granites, diabases and basalts. In addition, hydrogen is present in almost all silicates, in some deposits of coal and oil.

Physical and chemical properties. G. crystallizes in a cubic structure such as diamond, unit cell parameter a = 5, 6575 å. Density of solid G. 5.327 g/cm 3(25°C); liquid 5.557 (1000°C); t pl 937.5°C; t kip about 2700°C; thermal conductivity coefficient ~60 Tue/(m(To), or 0.14 cal/(cm(sec(hail) at 25°C. Even very pure hydrogel is brittle at ordinary temperatures, but above 550°C it is amenable to plastic deformation. G.'s hardness on a mineralogical scale is 6-6.5; compressibility coefficient (in the pressure range 0-120 Gn/m 2 or 0-12000 kgf/mm 2) 1.4 10 -7 m 2 /mn(1.4 10 -6 cm 2 / kgf); surface tension 0.6 n/m (600 dynes/cm). G. - a typical semiconductor with a band gap of 1.104 10 -19, or 0.69 ev(25°C); electrical resistivity G. high purity 0.60 ohm(m(60 ohm(cm) at 25°С; electron mobility 3900 and hole mobility 1900 cm 2 /in. sec(25°C) (when the content of impurities is less than 10 -8%). Transparent to infrared rays with a wavelength greater than 2 micron.

AT chemical compounds G. usually exhibits valences of 2 and 4, and compounds of 4-valent G. are more stable. At room temperature, G. is resistant to air, water, alkali solutions, and dilute hydrochloric and sulfuric acids, but easily dissolves in aqua regia and in an alkaline peroxide solution. hydrogen. Nitric acid slowly oxidizes. When heated in air to 500–700°C, hydroxide is oxidized to geo oxide and geo 2 dioxide. Dioxide G. - white powder with t pl 1116°C; solubility in water 4.3 g/l(20°C). According to the chemical properties of amphoteric, it dissolves in alkalis and with difficulty in mineral acids. Obtained by calcination of the hydrated precipitate (geo 2 . n h 2 o) released during the hydrolysis of gecl 4 tetrachloride. By fusing geo 2 with other oxides, derivatives of germanic acid can be obtained - metal germanates (in 2 ceo 3, na 2 ge O 3, etc.) - solids with high melting points.

Hydrocarbons interact with halogens to form the corresponding tetrahalides. The reaction proceeds most easily with fluorine and chlorine (already at room temperature), then with bromine (weak heating) and iodine (at 700-800°C in the presence of co). One of the most important compounds of G. gecl 4 tetrachloride is a colorless liquid; t pl-49.5°C; t kip 83.1°C; density 1.84 g/cm 3(20°C). Water strongly hydrolyzes with the release of a precipitate of hydrated dioxide. It is obtained by chlorination of metal hydroxide or by the interaction of geo 2 with concentrated HC1. G.'s dihalides of the general formula gex 2 , gecl monochloride, hexachlorodigermane ge 2 cl 6 and G.'s oxychlorides (for example, geocl 2) are also known.

Sulfur reacts vigorously with hydrogen at 900–1000°C to form ges 2 disulfide, a white solid t pl 825°C. Monosulfide ges and analogous compounds of hydrogen with selenium and tellurium, which are semiconductors, have also been described. Hydrogen slightly reacts with hydrogen at 1000–1100°C to form germine (geh) x, an unstable and easily volatile compound. By reacting germanides with dilute hydrochloric acid, germanic hydrogens of the series ge n h 2n+2 up to ge 9 h 20 can be obtained. Germylene of composition geh 2 is also known. G. does not directly react with nitrogen, however, there is ge 3 n 4 nitride, which is obtained by the action of ammonia on G. at 700-800 ° C. G. does not interact with carbon. G. forms compounds with many metals - germanides.

Numerous complex compounds of hydrogen are known, which are becoming increasingly important both in the analytical chemistry of hydrogen and in the processes of its preparation. G. forms complex compounds with organic hydroxyl-containing molecules (polyhydric alcohols, polybasic acids, etc.). Heteropolyacids of hydrogen were obtained. Just as for other elements of group IV, the formation of organometallic compounds is characteristic of hydrogen, an example of which is tetraethylgermane (c 2 h 5) 4 ge 3 .

Getting and using . In industrial practice, G. is obtained mainly from by-products of processing non-ferrous metal ores (zinc blende, zinc-copper-lead polymetallic concentrates) containing 0.001-0.1% G. Ashes from coal combustion, dust from gas generators and waste are also used as raw materials. coke plants. Initially, germanium concentrate (2-10% G.) is obtained from the listed sources in various ways, depending on the composition of the raw material. The extraction of hydrochloric acid from a concentrate usually includes the following stages: 1) chlorination of the concentrate with hydrochloric acid, its mixture with chlorine in an aqueous medium, or other chlorinating agents to obtain technical gecl 4 . To purify gecl 4, rectification and extraction of impurities with concentrated hcl are used. 2) Hydrolysis of gecl 4 and calcination of hydrolysis products to obtain geo 2 . 3) Recovery of geo with hydrogen or ammonia to metal. To isolate very pure hydrogen, which is used in semiconductor devices, zone melting metal. Single-crystal hydrogenation, necessary for the semiconductor industry, is usually obtained by zone melting or by the Czochralski method.

G. - one of the most valuable materials in modern semiconductor technology. It is used to make diodes, triodes, crystal detectors, and power rectifiers. Single-crystal hydrochloride is also used in dosimetric instruments and instruments that measure the intensity of constant and alternating magnetic fields. An important field of application of infrared technology is infrared technology, in particular the production of infrared radiation detectors operating in the 8-14 mk. Promising for practical use are many alloys that include galvanized glass, geo 2-based glasses, and other galvanized compounds.

Lit.: Tananaev I. V., Shpirt M. Ya., Germanium Chemistry, M., 1967; Ugay Ya. A., Introduction to the chemistry of semiconductors, M., 1965; Davydov V. I., Germany, M., 1964; Zelikman A. N., Krein O. E., Samsonov G. V., Metallurgy of rare metals, 2nd ed., M., 1964; Samsonov G. V., Bondarev V. N., Germanides, M., 1968.

B. A. Popovkin.

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