A chemical element discovered in 1886 in the rare mineral argyrodite found in Saxony. Dictionary of 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), a white-gray metallic element of the IV group of the periodic table of MENDELEEV, in which the properties of yet undiscovered elements were predicted, 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

Books

• Ion doping of semiconductors (silicon and germanium), J. Meyer, L. Erickson, J. Davis. The book is devoted to the method that has arisen in recent years of introducing impurity elements into semiconductors in the form of accelerated ions. The method allows one to control the density of impurity atoms and their depth…
• Life outside the Earth, V. Firsov. Advances in space exploration are forcing more and more attention to be paid to the problem of life outside the Earth: from the realm of science fiction, this problem is moving into the realm of scientific research. Book…

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. This compound owes its name 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 of the chemical element germanium? 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 prevents the formation of 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 is germanium used in modern semiconductor technology? 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 a complete description of a 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 germanium concentrate, grinding, as well as loading dioxide of this metal, occupational diseases. 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. Currently, there is no detailed information on how toxic germanium inorganic compounds are.

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

It is a strong irritant to the respiratory system, eyes, and skin. At a concentration of 13 mg/m 3 it is able to suppress the pulmonary response at the cellular level. With an increase in the concentration of this substance, there is a serious 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, with a half-life of 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 use of germanium is the creation of optics for thermal imaging cameras that operate in the wavelength range from 8 to 14 microns.

Such devices are used in military equipment for infrared guidance systems, night vision, passive thermal imaging, and fire fighting 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.

DEFINITION

Germanium is the thirty-second element of the Periodic Table. Designation - Ge from the Latin "germanium". Located in the fourth period, IVA group. Refers to semimetals. The nuclear charge is 32.

In the compact state, germanium has a silvery color (Fig. 1) and looks like a metal in appearance. At room temperature, it is resistant to air, oxygen, water, hydrochloric and dilute sulfuric acids.

Rice. 1. Germanium. Appearance.

Atomic and molecular weight of germanium

DEFINITION

Relative molecular weight of a substance (M r) is a number showing how many times the mass of a given molecule is greater than 1/12 of the mass of a carbon atom, and relative atomic mass of an element (A r)- how many times the average mass of atoms of a chemical element is greater than 1/12 of the mass of a carbon atom.

Since germanium exists in the free state in the form of monatomic Ge molecules, the values ​​of its atomic and molecular masses coincide. They are equal to 72.630.

Isotopes of germanium

It is known that germanium can occur in nature in the form of five stable isotopes 70 Ge (20.55%), 72 Ge (20.55%), 73 Ge (7.67%), 74 Ge (36.74%) and 76 Ge (7.67%). Their mass numbers are 70, 72, 73, 74 and 76, respectively. The nucleus of the germanium isotope 70 Ge contains thirty-two protons and thirty-eight neutrons, the remaining isotopes differ from it only in the number of neutrons.

There are artificial unstable radioactive isotopes of germanium with mass numbers from 58 to 86, among which the 68 Ge isotope with a half-life of 270.95 days is the longest-lived.

germanium ions

On the outer energy level of the germanium atom, there are four electrons that are valence:

1s 2 2s 2 2p 6 3s 2 3p 6 3d 10 4s 2 4p 2 .

As a result of chemical interaction, germanium gives up its valence electrons, i.e. is their donor, and turns into a positively charged ion:

Ge 0 -2e → Ge 2+;

Ge 0 -4e → Ge 4+ .

Molecule and atom of germanium

In the free state, germanium exists in the form of monatomic Ge molecules. Here are some properties that characterize the germanium atom and molecule:

Examples of problem solving

EXAMPLE 1

EXAMPLE 2

The task	Calculate the mass fractions of the elements that make up germanium (IV) oxide if its molecular formula is GeO 2 .
Solution	The mass fraction of an element in the composition of any molecule is determined by the formula: ω (X) = n × Ar (X) / Mr (HX) × 100%.

Germanium (from the Latin Germanium), designated "Ge", an element of the IVth group of the periodic table of chemical elements of Dmitry Ivanovich Mendeleev; element number 32, atomic mass is 72.59. Germanium is a gray-white solid with a metallic luster. Although the color of germanium is a rather relative concept, it all depends on the surface treatment of the material. Sometimes it can be gray as steel, sometimes silvery, and sometimes completely black. Outwardly, germanium is quite close to silicon. These elements are not only similar to each other, but also have largely the same semiconductor properties. Their essential difference is the fact that germanium is more than twice as heavy as silicon.

Germanium, found in nature, is a mixture of five stable isotopes with mass numbers 76, 74, 73, 32, 70. Back in 1871, the famous chemist, "father" of the periodic table, Dmitry Ivanovich Mendeleev predicted the properties and existence of germanium. He called the element unknown at that time "ekasilicium", because. the properties of the new substance were in many respects similar to those of silicon. In 1886, after studying the mineral argyrdite, the German forty-eight-year-old chemist K. Winkler discovered a completely new chemical element in the natural mixture.

At first, the chemist wanted to call the element neptunium, because the planet Neptune was also predicted much earlier than it was discovered, but then he learned that such a name had already been used in the false discovery of one of the elements, so Winkler decided to abandon this name. The scientist was offered to name the element angular, which means “controversial, angular”, but Winkler did not agree with this name either, although element No. 32 really caused a lot of controversy. The scientist was German by nationality, so he eventually decided to name the element germanium, in honor of his native country of Germany.

As it turned out later, germanium turned out to be nothing more than the previously discovered “ekasilicium”. Up until the second half of the twentieth century, the practical usefulness of germanium was rather narrow and limited. The industrial production of metal began only as a result of the beginning of the industrial production of semiconductor electronics.

Germanium is a semiconductor material widely used in electronics and engineering, as well as in the production of microcircuits and transistors. Radar installations use thin films of germanium, which are applied to glass and used as resistance. Alloys with germanium and metals are used in detectors and sensors.

The element does not have such strength as tungsten or titanium, it does not serve as an inexhaustible source of energy like plutonium or uranium, the electrical conductivity of the material is also far from the highest, and iron is the main metal in industrial technology. Despite this, germanium is one of the most important components of the technical progress of our society, because. it even earlier than silicon began to be used as a semiconductor material.

In this regard, it would be appropriate to ask: What is semiconductivity and semiconductors? Even experts cannot answer this question exactly, because. we can talk about the specifically considered property of semiconductors. There is also an exact definition, but only from the field of folklore: A semiconductor is a conductor for two cars.

A bar of germanium costs almost the same as a bar of gold. The metal is very fragile, almost like glass, so if you drop such an ingot, there is a high probability that the metal will simply break.

Germanium metal, properties

Biological properties

For medical needs, germanium was most widely used in Japan. The results of tests of organogermanium compounds on animals and humans have shown that they are able to have a beneficial effect on the body. In 1967, the Japanese doctor K. Asai discovered that organic germanium has a wide biological effect.

Among all its biological properties, it should be noted:

• - ensuring the transfer of oxygen to the tissues of the body;
• - increasing the immune status of the body;
• - manifestation of antitumor activity.

Subsequently, Japanese scientists created the world's first medical product containing germanium - "Germanium - 132".

In Russia, the first domestic drug containing organic germanium appeared only in 2000.

The processes of biochemical evolution of the surface of the earth's crust did not have the best effect on the content of germanium in it. Most of the element has been washed from the land into the oceans, so that its content in the soil remains quite low.

Among plants that have the ability to absorb germanium from the soil, the leader is ginseng (germanium up to 0.2%). Germanium is also found in garlic, camphor and aloe, which are traditionally used in the treatment of various human diseases. In vegetation, germanium is found in the form of carboxyethyl semioxide. Now it is possible to synthesize sesquioxanes with a pyrimidine fragment - organic compounds of germanium. This compound in its structure is close to natural, as in the root of ginseng.

Germanium can be attributed to rare trace elements. It is present in a large number of different products, but in meager doses. The daily intake of organic germanium is set at 8-10 mg. An assessment of 125 foodstuffs showed that about 1.5 mg of germanium enters the body daily with food. The content of the trace element in 1 g of raw foods is about 0.1 - 1.0 μg. Germanium is found in milk, tomato juice, salmon, and beans. But in order to satisfy daily requirement in Germany, you should drink 10 liters daily tomato juice or eat about 5 kilograms of salmon. From the point of view of the cost of these products, the physiological properties of a person, and common sense, the use of such a quantity of germanium-containing products is also not possible. On the territory of Russia, about 80-90% of the population has a lack of germanium, which is why special preparations have been developed.

Practical studies have shown that in the body germanium is most of all in the current intestine, stomach, spleen, bone marrow and blood. The high content of the microelement in the intestines and stomach indicates a prolonged action of the process of absorption of the drug into the blood. There is an assumption that organic germanium behaves in the blood in much the same way as hemoglobin, i.e. has a negative charge and is involved in the transfer of oxygen to the tissues. Thus, it prevents the development of hypoxia at the tissue level.

As a result of repeated experiments, the property of germanium to activate T-killers and promote the induction of gamma interferons, which suppress the process of reproduction of rapidly dividing cells, was proved. The main direction of action of interferons is antitumor and antiviral protection, radioprotective and immunomodulatory functions of the lymphatic system.

Germanium in the form of sesquioxide has the ability to act on hydrogen ions H +, smoothing out their detrimental effect on body cells. The guarantee of excellent operation of all systems of the human body is the uninterrupted supply of oxygen to the blood and all tissues. Organic germanium not only delivers oxygen to all points of the body, but also promotes its interaction with hydrogen ions.

• - Germanium is a metal, but its brittleness can be compared to glass.
• - Some reference books state that germanium has a silvery color. But this cannot be said, because the color of germanium directly depends on the method of processing the surface of the metal. Sometimes it can appear almost black, other times it has a steely color, and sometimes it can be silvery.
• - Germanium was found on the surface of the sun, as well as in the composition of meteorites that fell from space.
• - For the first time, an organoelement compound of germanium was obtained by the discoverer of the element Clemens Winkler from germanium tetrachloride in 1887, it was tetraethylgermanium. Of all received present stage none of the organoelement compounds of germanium is poisonous. At the same time, most of the tin and organolead microelements, which are analogues of germanium in their physical properties, are toxic.
• - Dmitri Ivanovich Mendeleev predicted three chemical elements even before their discovery, including germanium, calling the element ekasilicium due to its similarity to silicon. The prediction of the famous Russian scientist was so accurate that it simply amazed scientists, incl. and Winkler, who discovered germanium. The atomic weight according to Mendeleev was 72, in reality it was 72.6; specific gravity according to Mendeleev was 5.5 in reality - 5.469; atomic volume according to Mendeleev was 13 in reality - 13.57; the highest oxide according to Mendeleev is EsO2, in reality - GeO2, its specific gravity according to Mendeleev was 4.7, in reality - 4.703; chloride compound according to Mendeleev EsCl4 - liquid, boiling point about 90 ° C, in fact - chloride compound GeCl4 - liquid, boiling point 83 ° C, compound with hydrogen according to Mendeleev EsH4 is gaseous, compound with hydrogen is actually GeH4 gaseous; organometallic compound according to Mendeleev Es(C2H5)4, boiling point 160 °C, organometallic compound in reality - Ge(C2H5)4 boiling point 163.5°C. As can be seen from the information reviewed above, Mendeleev's prediction was surprisingly accurate.
• - On February 26, 1886, Clemens Winkler began his letter to Mendeleev with the words "Dear Sir." He, in a rather polite manner, told the Russian scientist about the discovery of a new element, called germanium, which, in its properties, was nothing other than the previously predicted Mendeleev's "ekasilicium." Dmitri Ivanovich Mendeleev's answer was no less polite. The scientist agreed with the discovery of his colleague, calling germanium "the crown of his periodic system", and Winkler the "father" of the element worthy of wearing this "crown".
• - Germanium as a classical semiconductor has become the key to solving the problem of creating superconducting materials that operate at the temperature of liquid hydrogen, but not liquid helium. As you know, hydrogen passes into a liquid state from a gaseous state when the temperature reaches –252.6°C, or 20.5°K. In the 1970s, a film of germanium and niobium was developed, the thickness of which was only a few thousand atoms. This film is capable of maintaining superconductivity even at temperatures of 23.2°K and below.
• - When growing a germanium single crystal, a germanium crystal is placed on the surface of molten germanium - a “seed”, which is gradually raised using an automatic device, while the melt temperature slightly exceeds the melting point of germanium (937 ° C). The "seed" rotates so that the single crystal, as they say, "overgrown with meat" from all sides evenly. It should be noted that during such growth, the same thing happens as in the process of zone melting, i.e. practically only germanium passes into the solid phase, and all impurities remain in the melt.

History

The existence of such an element as germanium was predicted back in 1871 by Dmitry Ivanovich Mendeleev, due to its similarities with silicon, the element was called ekasilicium. In 1886, a professor at the Freiberg Mining Academy discovered argyrodite, a new silver mineral. Then this mineral was studied quite carefully by the professor of technical chemistry Clemens Winkler, conducting a complete analysis of the mineral. Forty-eight-year-old Winkler was rightfully considered the best analyst at the Freiberg Mining Academy, which is why he was given the opportunity to study argyrodite.

In a fairly short time, the professor was able to provide a report on the percentage of various elements in the original mineral: silver in its composition was 74.72%; sulfur - 17.13%; ferrous oxide - 0.66%; mercury - 0.31%; zinc oxide - 0.22%. But almost seven percent - it was the share of some incomprehensible element, which, it seems, had not yet been discovered at that distant time. In connection with this, Winkler decided to isolate the unidentified component of argyrodptus, to study its properties, and in the process of research he realized that he had actually found a completely new element - it was an explication predicted by D.I. Mendeleev.

However, it would be wrong to think that Winkler's work went smoothly. Dmitry Ivanovich Mendeleev, in addition to the eighth chapter of his book Fundamentals of Chemistry, writes: “At first (February 1886), the lack of material, as well as the absence of a spectrum in the flame and the solubility of germanium compounds, seriously hampered Winkler’s research ...” It is worth paying attention to the words “ no spectrum. But how so? In 1886 there was already a widely used method of spectral analysis. Using this method, elements such as thallium, rubidium, indium, cesium on Earth and helium on the Sun were discovered. Scientists already knew for certain that each chemical element without exception has an individual spectrum, and then suddenly there is no spectrum!

The explanation for this phenomenon appeared a little later. Germanium has characteristic spectral lines. Their wavelength is 2651.18; 3039.06 Ǻ and a few more. However, they all lie within the ultraviolet invisible part of the spectrum, it can be considered lucky that Winkler is an adherent of traditional methods of analysis, because it is these methods that led him to success.

Winkler's method of obtaining germanium from the mineral is quite close to one of the modern industrial methods for isolating the 32nd element. First, germanium, which was contained in argaroid, was converted into dioxide. Then the resulting white powder was heated to a temperature of 600-700 °C in a hydrogen atmosphere. In this case, the reaction turned out to be obvious: GeO 2 + 2H 2 → Ge + 2H 2 O.

It was by this method that the relatively pure element No. 32, germanium, was first obtained. At first, Winkler intended to name vanadium neptunium, after the planet of the same name, because Neptune, like germanium, was first predicted, and only then found. But then it turned out that such a name had already been used once, one chemical element, discovered falsely, was called neptunium. Winkler chose not to compromise his name and discovery, and abandoned neptunium. One French scientist Rayon suggested, however, later he recognized his proposal as a joke, he suggested calling the element angular, i.e. "controversial, angular", but Winkler did not like this name either. As a result, the scientist independently chose the name for his element, and named it germanium, in honor of his native country of Germany, over time, this name was established.

Until the 2nd floor. 20th century practical use of germanium remained rather limited. The industrial production of metal arose only in connection with the development of semiconductors and semiconductor electronics.

Being in nature

Germanium can be classified as a trace element. In nature, the element does not occur in its free form at all. The total metal content in the earth's crust of our planet by mass is 7 × 10 −4% %. This is more than the content of such chemical elements as silver, antimony or bismuth. But germanium's own minerals are quite scarce and very rare in nature. Almost all of these minerals are sulfosalts, for example, germanite Cu 2 (Cu, Fe, Ge, Zn) 2 (S, As) 4, confieldite Ag 8 (Sn,Ce)S 6, argyrodite Ag8GeS6 and others.

The main part of germanium dispersed in the earth's crust is contained in a huge number of rocks, as well as many minerals: sulfite ores of non-ferrous metals, iron ores, some oxide minerals (chromite, magnetite, rutile and others), granites, diabases and basalts. In the composition of some sphalerites, the content of the element can reach several kilograms per ton, for example, in frankeite and sulvanite 1 kg / t, in enargites the content of germanium is 5 kg / t, in pyrargyrite - up to 10 kg / t, but in other silicates and sulfides - tens and hundreds g/t. A small proportion of germanium is present in almost all silicates, as well as in some of the oil and coal deposits.

The main mineral of the element is germanium sulfite (formula GeS2). The mineral is found as an impurity in zinc sulfites and other metals. The most important germanium minerals are: germanite Cu 3 (Ge, Fe, Ga) (S, As) 4, plumbogermanite (Pb, Ge, Ga) 2 SO 4 (OH) 2 2H 2 O, stottite FeGe (OH) 6, rhenierite Cu 3 (Fe, Ge, Zn) (S, As) 4 and argyrodite Ag 8 GeS 6 .

Germanium is present in the territories of all states without exception. But none of the industrialized countries of the world has industrial deposits of this metal. Germanium is very, very dispersed. On Earth, minerals of this metal are considered to be very rare, the content of germanium in which is at least 1%. Such minerals include germanite, argyrodite, ultramafic, and others, including minerals discovered in recent decades: schtotite, renierite, plumbogermanite, and confieldite. The deposits of all these minerals are not able to meet the needs of modern industry in this rare and important chemical element.

The bulk of germanium is dispersed in minerals of other chemical elements, and is also found in natural waters, in coals, in living organisms and in soil. For example, the content of germanium in ordinary coal sometimes reaches more than 0.1%. But such a figure is quite rare, usually the share of germanium is lower. But there is almost no germanium in anthracite.

Receipt

During the processing of germanium sulfide, oxide GeO 2 is obtained, with the help of hydrogen it is reduced to obtain free germanium.

In industrial production, germanium is mined mainly as a by-product from the processing of non-ferrous metal ores (zinc blende, zinc-copper-lead polymetallic concentrates containing 0.001-0.1% germanium), ash from coal combustion, and some by-products of coke chemistry.

Initially, germanium concentrate (from 2% to 10% germanium) is isolated from the sources discussed above in various ways, the choice of which depends on the composition of the raw material. In the processing of boxing coals, germanium is partially precipitated (from 5% to 10%) into the tar water and resin, from there it is extracted in combination with tannin, after which it is dried and fired at a temperature of 400-500 ° C. The result is a concentrate that contains about 30-40% germanium, germanium is isolated from it in the form of GeCl 4 . The process of extracting germanium from such a concentrate, as a rule, includes the same stages:

1) The concentrate is chlorinated with hydrochloric acid, a mixture of acid and chlorine in an aqueous medium, or other chlorinating agents, which can result in technical GeCl 4 . In order to purify GeCl 4, rectification and extraction of impurities of concentrated hydrochloric acid are used.

2) Hydrolysis of GeCl 4 is carried out, the hydrolysis products are calcined until GeO 2 oxide is obtained.

3) GeO is reduced with hydrogen or ammonia to pure metal.

Upon receipt of the purest germanium, which is used in semiconductor technical means, the zone melting of the metal is carried out. Single-crystal germanium, necessary for semiconductor production, is usually obtained by zone melting or by the Czochralski method.

Methods for isolating germanium from tar waters of coke plants were developed by the Soviet scientist V.A. Nazarenko. In this raw material, germanium is not more than 0.0003%, however, using an oak extract from them, it is easy to precipitate germanium in the form of a tannide complex.

The main component of tannin is an ester of glucose, where the meta-digallic acid radical is present, which binds germanium, even if the concentration of the element in solution is very low. From the sediment, you can easily get a concentrate, the content of germanium dioxide in which is up to 45%.

Subsequent transformations will already depend little on the type of raw material. Germanium is reduced with hydrogen (as in the case of Winkler in the 19th century), however, germanium oxide must first be isolated from numerous impurities. The successful combination of the qualities of one germanium compound proved to be very useful for solving this problem.

Germanium tetrachloride GeCl4. is a volatile liquid that boils at just 83.1°C. Therefore, it is quite conveniently purified by distillation and rectification (in quartz columns with packing).

GeCl4 is almost insoluble in hydrochloric acid. This means that the dissolution of HCl impurities can be used to purify it.

Purified germanium tetrachloride is treated with water, purified with ion-exchange resins. A sign of the desired purity is an increase in the resistivity of water to 15-20 million ohm cm.

Hydrolysis of GeCl4 occurs under the action of water:

GeCl4 + 2H2O → GeO2 + 4HCl.

It can be seen that we have before us the "written backwards" equation for the reaction of obtaining germanium tetrachloride.

Then comes the reduction of GeO2 using purified hydrogen:

GeO2 + 2 H2O → Ge + 2 H2O.

As a result, powdered germanium is obtained, which is alloyed and then purified by the zone melting method. This purification method was developed back in 1952 specifically for the purification of germanium.

The impurities necessary to give germanium a particular type of conductivity are introduced at the final stages of production, namely during zone melting, as well as during the growth of a single crystal.

Application

Germanium is a semiconductor material used in electronics and technology in the production of microcircuits and transistors. The thinnest films of germanium are applied to glass and used as resistance in radar installations. Alloys of germanium with various metals are used in the manufacture of detectors and sensors. Germanium dioxide is widely used in the production of glasses that have the property of transmitting infrared radiation.

Germanium telluride has been serving as a stable thermoelectric material for a very long time, as well as a component of thermoelectric alloys (thermo-mean emf with 50 μV/K). Ultra-high purity germanium plays an exceptionally strategic role in the manufacture of prisms and lenses for infrared optics. The largest consumer of germanium is infrared optics, which is used in computer technology, sighting and missile guidance systems, night vision devices, mapping and exploration of the earth's surface from satellites. Germanium is also widely used in fiber optic systems (adding germanium tetrafluoride to glass fibers), as well as in semiconductor diodes.

Germanium as a classical semiconductor has become the key to solving the problem of creating superconducting materials that operate at the temperature of liquid hydrogen, but not liquid helium. As you know, hydrogen passes into a liquid state from a gaseous state when the temperature reaches -252.6°C, or 20.5°K. In the 1970s, a film of germanium and niobium was developed, the thickness of which was only a few thousand atoms. This film is capable of maintaining superconductivity even at temperatures of 23.2°K and below.

By fusing indium into the HES plate, thus creating a region with the so-called hole conductivity, a rectifying device is obtained, i.e. diode. The diode has the property to pass electric current in one direction: the electron region from the region with hole conduction. After indium is fused on both sides of the HES plate, this plate becomes the basis of the transistor. For the first time in the world, a germanium transistor was created back in 1948, and after only twenty years similar devices produced in the hundreds of millions.

Diodes based on germanium and triodes have become widely used in televisions and radios, in a wide variety of measuring equipment and calculating devices.

Germanium is also used in other especially important areas of modern technology: in measuring low temperatures, in detecting infrared radiation, etc.

The use of the broom in all these areas requires germanium of very high chemical and physical purity. Chemical purity is such a purity at which the amount of harmful impurities should not be more than one ten-millionth of a percent (10-7%). Physical purity means a minimum of dislocations, a minimum of disturbances in the crystal structure of a substance. To achieve it, single-crystal germanium is specially grown. IN this case the entire ingot of metal is just one crystal.

To do this, a germanium crystal is placed on the surface of molten germanium - a “seed”, which gradually rises using an automatic device, while the melt temperature slightly exceeds the melting point of germanium (937 ° C). The "seed" rotates so that the single crystal, as they say, "overgrown with meat" from all sides evenly. It should be noted that during such growth, the same thing happens as in the process of zone melting, i.e. practically only germanium passes into the solid phase, and all impurities remain in the melt.

Physical properties

Probably, few of the readers of this article had to visually see vanadium. The element itself is quite scarce and expensive, they do not make consumer goods from it, and their germanium filling, which happens in electrical appliances, is so small that it is not possible to see the metal.

Some reference books state that germanium is silver in color. But this cannot be said, because the color of germanium directly depends on the method of processing the surface of the metal. Sometimes it can appear almost black, other times it has a steely color, and sometimes it can be silvery.

Germanium is such a rare metal that the cost of its ingot can be compared with the cost of gold. Germanium is characterized by increased brittleness, which can only be compared with glass. Outwardly, germanium is quite close to silicon. These two elements are both competitors for the title of the most important semiconductor and analogues. Although some of the technical properties of the element are largely similar, as regards the appearance of the materials, it is very easy to distinguish germanium from silicon, germanium is more than twice as heavy. The density of silicon is 2.33 g/cm3 and the density of germanium is 5.33 g/cm3.

But it is impossible to speak unambiguously about the density of germanium, because. the figure 5.33 g/cm3 refers to germanium-1. This is one of the most important and most common modification of the five allotropic modifications of the 32nd element. Four of them are crystalline and one is amorphous. Germanium-1 is the lightest of the four crystalline modifications. Its crystals are built exactly the same as diamond crystals, a = 0.533 nm. However, if this structure is maximally dense for carbon, then germanium also has denser modifications. Moderate heat and high pressure (about 30 thousand atmospheres at 100 ° C) converts germanium-1 into germanium-2, the crystal lattice structure of which is exactly the same as that of white tin. We use the same method to obtain germanium-3 and germanium-4, which are even denser. All these "not quite ordinary" modifications are superior to germanium-1 not only in density, but also in electrical conductivity.

The density of liquid germanium is 5.557 g/cm3 (at 1000°C), the melting temperature of the metal is 937.5°C; the boiling point is about 2700°C; the value of the thermal conductivity coefficient is approximately 60 W / (m (K), or 0.14 cal / (cm (sec (deg)) at a temperature of 25 ° C. At ordinary temperatures, even pure germanium is fragile, but when it reaches 550 ° C, it begins to succumb On the mineralogical scale, the hardness of germanium is from 6 to 6.5, the value of the compressibility coefficient (in the pressure range from 0 to 120 H / m 2, or from 0 to 12000 kgf / mm 2) is 1.4 10-7 m 2 /mn (or 1.4 10-6 cm 2 /kgf), the surface tension is 0.6 n/m (or 600 dynes/cm).

Germanium is a typical semiconductor with a band gap size of 1.104·10 -19 or 0.69 eV (at 25°C); in high purity germanium, the electrical resistivity is 0.60 ohm (m (60 ohm (cm) (25 ° C); the electron mobility index is 3900, and the hole mobility is 1900 cm 2 / in. sec (at 25 ° C and at content from 8% of impurities.) For infrared rays, the wavelength of which is more than 2 microns, the metal is transparent.

Germanium is rather brittle, it cannot be hot or cold worked by pressure below 550 °C, but if the temperature rises, the metal becomes ductile. The hardness of the metal on the mineralogical scale is 6.0-6.5 (germanium is sawn into plates using a metal or diamond disk and an abrasive).

Chemical properties

Germanium, being in chemical compounds, usually exhibits the second and fourth valencies, but compounds of tetravalent germanium are more stable. Germanium at room temperature is resistant to the action of water, air, as well as alkali solutions and dilute concentrates of sulfuric or hydrochloric acid, but the element dissolves quite easily in aqua regia or an alkaline solution of hydrogen peroxide. The element is slowly oxidized by the action of nitric acid. Upon reaching a temperature of 500-700 ° C in air, germanium begins to oxidize to GeO 2 and GeO oxides. (IV) germanium oxide is a white powder with a melting point of 1116°C and a solubility in water of 4.3 g/l (at 20°C). According to its chemical properties, the substance is amphoteric, soluble in alkali, with difficulty in mineral acid. It is obtained by penetration of the hydrated precipitate GeO 3 nH 2 O, which is released during hydrolysis. Germanium acid derivatives, for example, metal germanates (Na 2 GeO 3 , Li 2 GeO 3 , etc.) are solids with high melting points, can be obtained by fusing GeO 2 and other oxides.

As a result of the interaction of germanium and halogens, the corresponding tetrahalides can be formed. The reaction is easiest to proceed with chlorine and fluorine (even at room temperature), then with iodine (temperature 700-800 ° C, presence of CO) and bromine (with low heating). One of the most important germanium compounds is tetrachloride (formula GeCl 4). It is a colorless liquid with a melting point of 49.5°C, a boiling point of 83.1°C and a density of 1.84 g/cm3 (at 20°C). The substance is strongly hydrolyzed by water, releasing a precipitate of hydrated oxide (IV). The tetrachloride is obtained by chlorination of metallic germanium or by the interaction of GeO 2 oxide and concentrated hydrochloric acid. Germanium dihalides with the general formula GeX 2 , hexachlorodigermane Ge 2 Cl 6 , GeCl monochloride, as well as germanium oxychlorides (for example, CeOCl 2) are also known.

Upon reaching 900-1000 ° C, sulfur interacts vigorously with germanium, forming GeS 2 disulfide. It is a white solid with a melting point of 825°C. The formation of GeS monosulfide and similar compounds of germanium with tellurium and selenium, which are semiconductors, are also possible. At a temperature of 1000–1100 °C, hydrogen slightly reacts with germanium, forming germine (GeH) X, which is an unstable and highly volatile compound. Germanic hydrogens of the series Ge n H 2n + 2 to Ge 9 H 20 can be formed by reacting germanides with dilute HCl. Germylene is also known with the composition GeH 2 . Germanium does not react directly with nitrogen, but there is Ge 3 N 4 nitride, which is obtained by the action of ammonia on germanium (700-800 ° C). Germanium does not interact with carbon. With many metals, germanium forms various compounds - germanides.

Many complex compounds of germanium are known, which are becoming increasingly important in the analytical chemistry of the element germanium, as well as in the processes of obtaining a chemical element. Germanium is able to form complex compounds with hydroxyl-containing organic molecules (polyhydric alcohols, polybasic acids, and others). There are also germanium heteropoly acids. Like other elements of the IVth group, germanium characteristically forms organometallic compounds. An example is tetraethylgermane (C 2 H 5) 4 Ge 3 .

IN human body contains a huge amount of micro and macro elements, without which the full functioning of all organs and systems would be simply impossible. Some of them people hear about all the time, and others are completely unaware of the existence of others, but they all play a role in good health. The latter group also includes germanium contained in the human body in an organic form. What kind of element it is, what processes it is responsible for and what level of it is considered the norm - read on.

Description and characteristics

In a general sense, germanium is one of the chemical elements presented in the famous periodic table (belongs to the fourth group). In nature, it is presented as a solid, gray-white substance with a metallic sheen, but in the human body it is contained in an organic form.

It must be said that it cannot be called very rare, since it is found in iron and sulfide ores and silicates, although germanium practically does not form its own minerals. The content of a chemical element in the Earth's crust exceeds the concentration of silver, antimony and bismuth several times, and in some minerals its amount reaches 10 kg per ton. The waters of the oceans contain about 6 10-5 mg/l of germanium.

Many plants growing on different continents are able to absorb a small amount of this chemical element and its compounds from the soil, after which they can enter the human body. In organic form, all such components are directly involved in various metabolic and recovery processes, which will be discussed later.

Did you know?For the first time this chemical element was noticed in 1886, and they learned about it thanks to the efforts of the German chemist K. Winkler. True, up to this point, Mendeleev (in 1869) also spoke about its existence, who at first conditionally called it “ekasilicium”.

Functions and role in the body

More recently, scientists believed that germanium is completely useless for humans and, in principle, performs absolutely no function in the body of living organisms. Nevertheless, today it is known for sure that individual organic compounds of this chemical element can be successfully used even as medicinal formulations, although it is too early to talk about their effectiveness.

Experiments conducted on laboratory rodents have shown that even a small amount of germanium can increase the lifespan of animals by 25-30%, and this in itself is a good reason to think about its benefits to humans.
Already conducted studies of the role of organic germanium in the human body make it possible to distinguish the following biological functions of this chemical element:

• prevention of oxygen starvation of the body by transferring oxygen to the tissues (the risk of the so-called "blood hypoxia", which manifests itself with a decrease in the amount of hemoglobin in erythrocytes, is reduced);
• stimulation of the development of the protective functions of the body by suppressing the processes of the spread of microbial cells and the activation of specific immunity cells;
• active antifungal, antiviral and antibacterial effects due to the production of interferon, which protects the body from harmful microorganisms;
• powerful antioxidant effect, expressed in the blocking of free radicals;
• delay in the development of tumor neoplasms and prevention of the formation of metastases (in this case, germanium neutralizes the action of negatively charged particles);
• acts as a regulator of the valve systems of digestion, the venous system and peristalsis;
• by stopping the movement of electrons in nerve cells, germanium compounds help to reduce a variety of pain manifestations.

All ongoing experiments involving the determination of the distribution rate of germanium in the human body after its oral use showed that 1.5 hours after ingestion, most of this element is found in the stomach, small intestine, spleen, bone marrow, and, of course, in blood. I.e, high level germanium in the organs of the digestive system proves its prolonged action when absorbed into the bloodstream.

Important! You should not independently check the effect of the indicated chemical element on yourself, because an incorrect calculation of the dosage may well lead to serious poisoning.

What contains germanium: products sources

Any microelement in our body performs a certain function, therefore, for good health and maintaining tone, it is so important to ensure the optimal level of certain components. This also applies to Germany. You can replenish its reserves daily by consuming garlic (this is where it is found the most), wheat bran, legumes, porcini mushrooms, tomatoes, fish and seafood (in particular, shrimp and mussels), and even wild garlic and aloe.
It is possible to enhance the effect of germanium on the body with the help of selenium. Many of these products can be easily found in the house of every housewife, so no difficulties should arise.

Daily requirement and norms

It is no secret that an excess of even useful components can harm no less than their shortage, therefore, before proceeding to replenish the lost amount of germanium, it is important to know about its allowable daily intake. Typically, this value ranges from 0.4 to 1.5 mg and depends on the age of the person and the existing trace element deficiency.

The human body copes well with the absorption of germanium (the absorption of this chemical element is 95%) and distributes it relatively evenly over tissues and organs (it doesn’t matter if we are talking about extracellular or intracellular space). The withdrawal of germanium to the outside occurs along with the urine (up to 90% comes out).

Scarcity and surplus

As we mentioned above, any extreme is not good. That is, both a shortage and an excess of the amount of germanium in the body can adversely affect its functional characteristics. So, with a microelement deficiency (resulting from its limited consumption with food or metabolic disorders in the body), osteoporosis and demineralization of bone tissue may develop, and the possibility of oncological conditions increases several times.

An excessive amount of germanium has a toxic effect on the body, and compounds of the two-year-old element are considered especially dangerous. In most cases, its excess can be explained by the inhalation of pure vapors under industrial conditions (MAC in air can be 2 mg/m3). In direct contact with germanium chloride, local skin irritations are not excluded, and its ingestion into the body is often fraught with damage to the liver and kidneys.

Did you know?For medical purposes, the described element was first interested in the Japanese, and a real breakthrough in this direction was the study of Dr. Asai, who discovered a wide range of biological effects of germanium.

As you can see, the described trace element is really needed by our body, even if its role has not yet been fully studied. Therefore, to maintain an optimal balance, simply eat more of the listed products and try not to be in harmful working conditions.