The chemical element germanium is in the fourth group (the main subgroup) in the periodic table. It belongs to the family of metals, its relative atomic mass is 73. By mass, the germanium content in the earth's crust is estimated at 0.00007 percent by mass.
Discovery story
The chemical element germanium was established due to the forecasts of Dmitry Ivanovich Mendeleev. It was they who predicted the existence of ecasilicia, and recommendations were given on its search.
Russian chemist believed that this metal element is 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 discovered, called argyrodite. This compound owes its name to silver found in this mineral.
The chemical element germanium in the composition was discovered only after a group of chemists from the Mining Academy of Freiberg began research. Under the leadership of C. Winkler, they found that zinc and iron oxides, as well as sulfur and mercury account for only 93 percent of the mineral. Winkler suggested that the remaining seven percent came from a chemical element unknown at that time. After additional chemical experiments, germanium was discovered. The chemist announced his discovery in a report, presented the information received about 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 him Neptune, but this name has already been used. Then they began to call him germanium. The chemical element discovered by Winkler caused a serious discussion between the leading chemists of the time. The German scientist Richter suggested that this is the same ecasilicium that Mendeleev spoke about. After some time, 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 numbers in the periodic table. This metal melts at 937.4 ° C. The boiling point of this substance is 2700 ° C.
Interesting Facts
Germanium is an element that was first used in Japan for medical purposes. After numerous studies of organo-germanium compounds carried out on animals, as well as in human studies, it was possible to detect the positive effect of such ores on living organisms. In 1967, Dr. K. Asai was able to discover 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 throughout 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 and prevents the development of metastases. The 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 of its fields of application. In Germany, this element was mainly obtained as a by-product of the processing of non-ferrous ores. In various ways, which depend on the composition of the feedstock, germanium concentrate was isolated. Its composition 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, crystal detectors. Germanium is also used to create dosimetric devices, devices that are necessary to measure the intensity of a constant and alternating magnetic field.
A significant area of application of this metal is the manufacture of infrared radiation detectors.
The use of not only Germany itself, but also some of its compounds is promising.
Chemical properties
Germanium at room temperature is quite resistant to moisture and oxygen.
In a number of chemical elements (silicon - germanium - tin), an increase in reducing ability is observed.
Germanium is resistant to hydrochloric and sulfuric acid solutions; it does not interact with alkali solutions. Moreover, this metal dissolves quite quickly in aqua regia (seven nitric and hydrochloric acids), as well as in an alkaline solution of hydrogen peroxide.
How to give a full description of a chemical element? Germanium and its alloys must be analyzed not only by their physical and chemical properties, but also by their fields of application. The process of oxidation of germanium with nitric acid proceeds rather slowly.
Being in nature
Let’s try to characterize a chemical element. Germanium in nature is found only in the form of compounds. Among the most common germanium-containing minerals in nature, we distinguish germanite and argyrodite. In addition, germanium is present in zinc sulfides and silicates, and in small amounts it is in various types of coal.
Health hazard
What effect does germanium have on the body? A chemical element whose electronic formula has the form 1e; 8 e; 18 e; 7 e, can negatively affect the human body. For example, when loading a germanium concentrate, grinding, and also loading a dioxide of a given metal, occupational diseases can occur. Other sources of harm to health can be considered the process of re-melting germanium powder into bars, the production of carbon monoxide.
Adsorbed germanium can be removed quite quickly from the body, to a greater extent with urine. There is currently no detailed information on how toxic inorganic compounds of germanium are.
Germanium tetrachloride has an irritating effect on the skin. In clinical trials, as well as with prolonged oral administration of cumulative amounts that reached 16 grams of spiro germanium (an organic antitumor drug), as well as other germanium compounds, the nephrotoxic and neurotoxic activity of this metal was found.
Such dosages are generally not characteristic of industrial enterprises. Those experiments that were conducted on animals were aimed at studying the effects of germanium and its compounds on a living organism. As a result, it was possible to establish a deterioration in health by inhaling a substantial volume of dust of metallic germanium, as well as its dioxide.
Scientists have discovered serious morphological changes in the lungs of animals that 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 skin of the eye leads to the formation of germanic acid, which is a serious eye irritant. With prolonged intraperitoneal injections, serious changes in peripheral blood were detected.
Important facts
The most harmful germanium compounds are chloride and germanium hydride. The latter substance provokes serious poisoning. As a result of morphological examination of the organs of animals that died in the acute phase, showed significant violations in the circulatory system, as well as cellular modifications in the parenchymal organs. Scientists came to the conclusion that hydride is a multi-purpose poison that affects the nervous system, inhibits the peripheral blood circulation system.
Germany 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, serious irritation of the upper respiratory tract, significant changes in the rhythm and respiratory rate are observed.
Poisoning with this substance leads to catarrh-desquamative bronchitis, interstitial pneumonia.
Getting
Since germanium is present in nature as an impurity to nickel, polymetallic, and tungsten ores, several labor-intensive processes associated with ore dressing are carried out in industry to isolate pure metal. First, germanium oxide is isolated from it, then it is reduced with hydrogen at elevated temperature to obtain a simple metal:
GeO2 + 2H2 = Ge + 2H2O.
Electronic properties and isotopes
Germanium is considered an indirect typical semiconductor. The value of its dielectric permittivity is 16, and the electron affinity is 4 eV.
In a thin film doped with gallium, it is possible to give superconductivity to germanium.
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 ultrahigh purity metallic germanium is important for the manufacture of optical elements of infrared optics: prisms, lenses, and optical windows of modern sensors. The most common area of use for Germany 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, and fire-fighting systems. Germanium also 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 elements are significantly higher than those of their silicon counterparts, which can significantly increase the efficiency of such radio devices. Considering that germanium is not as common in nature as silicon, silicon semiconductor elements are mainly used in radio devices.