Application of crystals in science and technology

The applications of crystals in science and technology are so numerous and varied that they are difficult to list. Therefore, we will limit ourselves to a few examples.

The hardest and rarest of natural minerals is diamond. Today, a diamond is primarily a working stone, not a decoration stone.

Due to its exceptional hardness, diamond plays a huge role in technology. Diamond saws are used to cut stones. A diamond saw is a large (up to 2 meters in diameter) rotating steel disk, on the edges of which cuts or notches are made. Fine diamond powder mixed with some adhesive substance is rubbed into these cuts. Such a disk, rotating with high speed, quickly saws any stone.

Diamond is of enormous importance when drilling rocks and in mining operations.

Diamond points are inserted into engraving tools, dividing machines, hardness testing apparatus, and drills for stone and metal.

Diamond powder is used to grind and polish hard stones, hardened steel, hard and super-hard alloys. The diamond itself can only be cut, polished and engraved with diamond. The most critical engine parts in automotive and aircraft production are processed with diamond cutters and drills.

Ruby and sapphire are among the most beautiful and most expensive of precious stones. All these stones have other qualities, more modest, but useful. Blood-red ruby and blue-blue sapphire are siblings, they are generally the same mineral - corundum, aluminum oxide A12O3. The difference in color arose due to very small impurities in aluminum oxide: an insignificant addition of chromium turns colorless corundum into a blood-red ruby, titanium oxide into sapphire. There are corundums of other colors. They also have a completely modest, nondescript brother: brown, opaque, fine corundum - emery, which is used to clean metal, from which sandpaper is made. Corundum with all its varieties is one of the hardest stones on Earth, the hardest after diamond. Corundum can be drilled, ground, polished, and sharpened stone and metal. Made from corundum and emery grinding wheels and whetstones, grinding powders.

The entire watch industry runs on artificial rubies. At semiconductor factories, the finest circuits are drawn with ruby needles. In the textile and chemical industries, ruby thread guides draw threads from artificial fibers, nylon, and nylon.

New life ruby is a laser or, as it is called in science, an optical quantum generator (OQG), a wonderful device of our days. In 1960 The first ruby laser was created. It turned out that the ruby crystal amplifies the light. The laser shines brighter than a thousand suns.

A powerful laser beam with enormous power. It burns through easily sheet metal, welds metal wires, burns metal pipes, drills the finest holes in hard alloys and diamond. These functions are performed by a solid laser, which uses ruby, garnet and neodite. In eye surgery, neodyne lasers and ruby lasers are most often used. In ground-based short-range systems, gallium arsenide injection lasers are often used.

New laser crystals have also appeared: fluorite, garnets, gallium arsenide, etc.

Sapphire is transparent, so plates for optical instruments are made from it.

The bulk of sapphire crystals goes to the semiconductor industry.

Flint, amethyst, jasper, opal, chalcedony - all these are varieties of quartz. Small grains of quartz form sand. And the most beautiful, most wonderful variety of quartz is rhinestone, i.e. transparent quartz crystals. Therefore, lenses, prisms and other parts of optical instruments are made from transparent quartz.

The electrical properties of quartz are especially amazing. If you compress or stretch a quartz crystal, electrical charges appear on its edges. This is the piezoelectric effect in crystals.

Nowadays, not only quartz is used as piezoelectrics, but also many other, mainly artificially synthesized substances: blue salt, barium titanate, potassium and ammonium dihydrogen phosphates (KDP and ADP) and many others.

Piezoelectric crystals are widely used for reproduction, recording and transmission of sound.

There are also piezoelectric methods for measuring blood pressure in human blood vessels and the pressure of juices in the stems and trunks of plants. Piezoelectric plates are used to measure, for example, the pressure in the barrel of an artillery gun when fired, the pressure at the moment of a bomb explosion, instantaneous pressure in engine cylinders during an explosion in them hot gases.

The edectro-optical industry is the industry of crystals that do not have a center of symmetry. This industry is very large and diverse; its factories grow and process hundreds of types of crystals for use in optics, acoustics, radio electronics, and laser technology.

The polycrystalline material Polaroid has also found its use in technology.

Polaroid is thin transparencies, completely filled with tiny transparent needle-shaped crystals of a substance that birefringents and polarizes light. All crystals are located parallel to each other, so they all equally polarize the light passing through the film.

Polaroid films are used in polaroid glasses. Polaroids cancel out the glare of reflected light, allowing all other light to pass through. They are indispensable for polar explorers who constantly have to look at the dazzling reflection sun rays from the frozen snow field.

Polaroid glasses will help prevent collisions with oncoming cars, which very often occur due to the fact that the lights of the oncoming car blind the driver, and he does not see this car. If the windshields of cars and the glasses of car headlights are made of Polaroid, and both polaroids are rotated so that their optical axes are shifted, then the windshield will not let in the light of the headlights of an oncoming car, and will “extinguish it.”

The crystals played important role In many technical innovations 20th century Some crystals generate electric charge when deformed. Their first significant application was the manufacture of radio frequency oscillators stabilized by quartz crystals. By causing the quartz plate to vibrate electric field radio frequency oscillating circuit, you can thereby stabilize the receiving or transmitting frequency.
Semiconductor devices, which revolutionized electronics, are made from crystalline substances, mainly silicon and germanium. In this case, alloying impurities that are introduced into the crystal lattice play an important role. Semiconductor diodes are used in computers and communication systems, transistors have replaced vacuum tubes in radio engineering, and solar panels, placed on outer surface space aircraft, transform solar energy to electric. Semiconductors are also widely used in converters alternating current to permanent.
Crystals are also used in some masers to amplify microwave waves and in lasers to amplify light waves. Crystals with piezoelectric properties are used in radio receivers and transmitters, in pickup heads and in sonar. Some crystals modulate light beams, while others generate light under the influence of an applied voltage. The list of uses for crystals is already quite long and is constantly growing.

Applications of crystals in science and technology The applications of crystals in science and technology are so numerous and varied that they are difficult to list.

Diamond The hardest and rarest of natural minerals, diamond. Today, a diamond is primarily a worker stone, not a decoration stone.

Due to its exceptional hardness, diamond plays a huge role in technology. Diamond saws are used to cut stones. A diamond saw is a large (up to 2 meters in diameter) rotating steel disk, on the edges of which cuts or notches are made. Fine diamond powder mixed with some kind of adhesive substance is rubbed into these cuts. Such a disk, rotating at high speed, quickly saws any stone.

Diamond is of enormous importance when drilling rocks and in mining operations. Diamond points are inserted into engraving tools, dividing machines, hardness testing apparatus, and drills for stone and metal. Diamond powder is used to grind and polish hard stones, hardened steel, hard and super-hard alloys. The diamond itself can only be cut, polished and engraved with diamond. The most critical engine parts in automotive and aircraft production are processed with diamond cutters and drills.

Ruby and sapphire are among the most beautiful and most expensive of precious stones. All these stones have other qualities, more modest, but useful. Blood red ruby and blue sapphire are siblings, they are generally the same mineral corundum, aluminum oxide A 12 O 3. The difference in color arose due to very small impurities in aluminum oxide: an insignificant addition of chromium turns colorless corundum into blood red ruby, titanium oxide into sapphire. There are corundums of other colors. They also have a modest, nondescript brother: brown, opaque, fine corundum emery, which is used to clean the metal from which sandpaper is made. Corundum, with all its varieties, is one of the hardest stones on Earth, the hardest after diamond.

The entire watch industry runs on artificial rubies. In semiconductor factories, the finest circuits are drawn with ruby needles. In the textile and chemical industries, ruby yarn guides draw threads from artificial fibers, nylon, and nylon.

A powerful laser beam with enormous power. It easily burns through sheet metal, welds metal wires, burns through metal pipes, and drills the thinnest holes in hard alloys and diamond. These functions are performed by a solid laser, which uses ruby, garnet and neodite. In eye surgery, neodyne lasers and ruby lasers are most often used. In ground-based short-range systems, gallium arsenide injection lasers are often used.

Flint, amethyst, jasper, opal, chalcedony are all varieties of quartz. Small grains of quartz form sand.

And the most beautiful, most wonderful variety of quartz is rock crystal, that is, transparent quartz crystals. Therefore, lenses, prisms and other parts of optical instruments are made from transparent quartz. The electrical properties of quartz are especially amazing. If you compress or stretch a quartz crystal, electrical charges appear on its edges. This is the piezoelectric effect in crystals.

Nowadays, not only quartz is used as piezoelectrics, but also many other, mainly artificially synthesized substances: synthetic salt, barium titanate, potassium and ammonium dihydrogen phosphates (KDA and ADR) and many others. Piezoelectric crystals are widely used to reproduce, record and transmit sound.

There are also piezoelectric methods for measuring blood pressure in human blood vessels and the pressure of juices in the stems and trunks of plants. Piezoelectric plates are used to measure, for example, the pressure in the barrel of an artillery gun when fired, the pressure at the moment of a bomb explosion, and the instantaneous pressure in engine cylinders during the explosion of hot gases in them.

The polycrystalline material Polaroid has also found its use in technology. Polaroid is a thin transparent film, completely filled with tiny transparent needle-shaped crystals of a substance that birefringes and polarizes light. All crystals are located parallel to each other, so they all equally polarize the light passing through the film. Polaroid films are used in polaroid glasses. Polaroids cancel out the glare of reflected light, allowing all other light to pass through. They are indispensable for polar explorers, who constantly have to look at the dazzling reflection of the sun's rays from an icy snow field.

Polaroid glasses will help prevent collisions with oncoming cars, which very often happen because the lights of the oncoming car blind the driver, and he does not see this car. If the windshields of cars and the glasses of car headlights are made of Polaroid, and both fields of the roid are rotated so that their optical axes are shifted, then the windshield will not let in the light of the headlights of an oncoming car, and will “extinguish it”.

Crystals played an important role in many technical innovations of the 20th century. Some crystals generate an electrical charge when deformed. Their first significant application was the manufacture of radio frequency oscillators stabilized by quartz crystals. By forcing a quartz plate to vibrate in the electric field of a radio frequency oscillatory circuit, it is possible to stabilize the receiving or transmitting frequency.

Crystals are also used in some masers to amplify microwave waves and in lasers to amplify light waves. Crystals with piezoelectric properties are used in radio receivers and transmitters, in pickup heads and in sonar. Some crystals modulate light beams, while others generate light under the influence of an applied voltage. The list of uses for crystals is already quite long and is constantly growing.

In nature, single crystals of most substances without cracks, impurities and other defects are extremely rare. This has led to many crystals being called gemstones by people over thousands of years. Diamond, ruby, sapphire, amethyst and other precious stones for a long time were valued very highly by people, mainly not for special mechanical or other physical properties, but only because of its rarity.

The development of science and technology has led to the fact that many precious stones or simply crystals rarely found in nature have become very necessary for the manufacture of parts of devices and machines, for scientific research. The demand for many crystals has increased so much that it was impossible to satisfy it by expanding the scale of production of old and searching for new natural deposits.

In addition, many branches of technology and especially scientific research increasingly require single crystals of very high chemical purity with a perfect crystal structure. Crystals found in nature do not meet these requirements, since they grow in conditions that are very far from ideal.

Thus, the task arose to develop technology artificially made single crystals of many elements and chemical compounds.

Development comparatively simple way making a “gemstone” causes it to cease to be precious. This is explained by the fact that most precious stones are crystals widely distributed in nature. chemical elements and connections. Thus, diamond is a carbon crystal, ruby and sapphire are aluminum oxide crystals with various impurities.

Let's consider the main methods of growing single crystals. At first glance, it may seem that crystallization from a melt is very simple. It is enough to heat the substance above its melting point, obtain a melt, and then cool it. In principle, this is the right way, but if special measures are not taken, then best case scenario a polycrystalline sample will be obtained. And if the experiment is carried out, for example, with quartz, sulfur, selenium, sugar, which, depending on the rate of cooling of their melts, can solidify in a crystalline or amorphous state, then there is no guarantee that an amorphous body will not be obtained.

In order to grow one single crystal, slow cooling is not enough. Need to cool one first small area melt and obtain a “seed” of a crystal in it, and then, by successively cooling the melt surrounding the “seed”, allow the crystal to grow throughout the entire volume of the melt. This process can be achieved by slowly lowering a crucible containing the melt through an opening in a vertical tube furnace. The crystal nucleates at the bottom of the crucible, since it first enters the area of greater low temperatures, and then gradually grows throughout the entire volume of the melt. The bottom of the crucible is specially made narrow, pointed to a cone, so that only one crystalline nucleus can be located in it.

This method is often used to grow crystals of zinc, silver, aluminum, copper and other metals, as well as sodium chloride, potassium bromide, lithium fluoride and other salts used in the optical industry. In one day you can grow a rock salt crystal weighing about a kilogram.

The disadvantage of the described method is contamination of the crystals by the crucible material.

The crucibleless method of growing crystals from a melt, which is used to grow, for example, corundum (rubies, sapphires), does not have this drawback. The finest aluminum oxide powder from grains 2-100 microns in size is poured out in a thin stream from the hopper, passes through an oxygen-hydrogen flame, melts and falls in the form of drops onto a rod of refractory material. The temperature of the rod is maintained slightly below the melting point of aluminum oxide (2030°C). Drops of aluminum oxide cool on it and form a crust of sintered corundum mass. Clock mechanism slow (10-20mm/h ) lowers the rod, and an uncut corundum crystal gradually grows on it.

As in nature, obtaining crystals from solution comes down to two methods. The first of these consists of slowly evaporating the solvent from a saturated solution, and the second of slowly decreasing the temperature of the solution. The second method is more often used. Water, alcohols, acids, molten salts and metals are used as solvents. A disadvantage of methods for growing crystals from solution is the possibility of contamination of the crystals with solvent particles.

The crystal grows from those areas of the supersaturated solution that immediately surround it. As a result, the solution near the crystal turns out to be less supersaturated than far from it. Since a supersaturated solution is heavier than a saturated one, there is always an upward flow of “used” solution above the surface of the growing crystal. Without such stirring of the solution, crystal growth would quickly cease. Therefore, the solution is often additionally stirred or the crystal is fixed on a rotating holder. This allows you to grow more advanced crystals.

The lower the growth rate, the better the crystals obtained. This rule applies to all growing methods. Sugar crystals and table salt easy to obtain from an aqueous solution at home. But, unfortunately, not all crystals can be grown so easily. For example, the production of quartz crystals from solution occurs at a temperature of 400°C and a pressure of 1000 atm .

The applications of crystals in science and technology are so numerous and varied that they are difficult to list. Therefore, we will limit ourselves to a few examples.

The hardest and rarest of natural minerals is diamond. In the entire history of mankind, only about 150 tons of it have been mined, although the global diamond mining industry now employs almost a million people. Today, a diamond is primarily a working stone, not a decoration stone. About 80% of all natural diamonds mined and all artificial diamonds are used in industry. The role of diamonds in modern technology is so great that, according to American economists, stopping the use of diamonds would lead to a halving of the US industrial capacity.

Approximately 80% of diamonds used in technology are used for sharpening tools and cutters of “superhard alloys”. Diamonds serve as supporting stones (bearings) in high-end chronometers for sea vessels and in other highly accurate navigation instruments. Diamond bearings show no signs of wear even after 25,000,000 revolutions.

Slightly inferior to diamond in hardness, it competes with it in variety. technical applications ruby - noble corundum, aluminum oxide Al 2 O 3 with a coloring admixture of chromium oxide. From 1 kg of synthetic ruby it is possible to produce about 40,000 watch support stones. Ruby rods turned out to be irreplaceable in factories for the production of fabrics from chemical fiber. To produce 1 m of artificial fiber fabric, hundreds of thousands of meters of fiber are required. Thread guides made of the hardest glass wear out in a few days when artificial fiber is pulled through them, agate thread guides can last up to two months, ruby thread guides turn out to be almost eternal.

A new area for the widespread use of rubies in scientific research and in technology opened with the invention of the ruby laser - a device in which a ruby rod serves as a powerful source of light emitted in the form of a thin beam of light.

An exceptional role has been played by crystals in modern electronics. Most semiconductor electronic devices are made from germanium or silicon crystals.

Living on an Earth composed of crystalline rocks, we, of course, cannot escape from the problem of crystallinity: we walk on crystals, build with crystals, process crystals in factories, grow them in laboratories, widely use them in technology and science, eat crystals, and receive treatment. them... The science of crystallography studies the variety of crystals. She comprehensively examines crystalline substances, studies their properties and structure. In ancient times, crystals were considered to be rare. Indeed, the discovery of large homogeneous crystals in nature is a rare phenomenon. However, finely crystalline substances are quite common. For example, almost all rocks: granite, sandstone, limestone are crystalline. As research methods improved, substances that were previously considered amorphous turned out to be crystalline. Now we know that even some parts of the body are crystalline, for example, the cornea of the eye, vitamins, the melin sheath of the nerves are crystals. Long haul searches and discoveries, from measuring the external shape of crystals in depth, to the subtleties of their atomic structure have not yet been completed. But now researchers have studied its structure quite well and are learning to control the properties of the crystals.

Crystals are beautiful, one might say some kind of miracle, they attract you; They say “a man of crystal soul” about someone who has a pure soul. Crystal means shining with light, like a diamond... And if we talk about crystals with a philosophical attitude, then we can say that this is a material that is an intermediate link between living and inanimate matter. Crystals can originate, age, and collapse. A crystal, when growing on a seed (on an embryo), inherits the defects of this very embryo. In general, one can give many examples that set one in such a philosophical mood, although of course there is a lot of evil here... For example, on television one can now hear about the direct connection between the degree of order of water molecules and words, with music, and that water changes depending on thoughts, on the health status of the observer. I don't take it seriously. In fact, there is a lot of quackery and speculation around science. But prayer is mediated, acts through the Holy Spirit and does not need to be mixed scientific approach and spiritual things.

But speaking quite seriously, now it is perhaps impossible to name a single discipline, not a single area of science and technology that could do without crystals. When I was working, doctors flocked to me and showed me patients’ kidney stones: they were interested in the environments in which crystal formation occurred. And we visited a lot of pharmacists, because tablets are compressed crystals. The absorption and dissolution of tablets depends on which edges these microcrystals are covered with. Vitamins, the myelin sheath of nerves, proteins, and viruses are all crystals. And our consultations brought great satisfaction, answering questions that arose...

The crystal has miraculous properties; it performs a variety of functions. These properties are inherent in its structure, which has a three-dimensional lattice structure.

An example of the use of crystals is the quartz crystal used in telephone handsets. If a quartz plate is mechanically affected, an electric charge will arise in it in the appropriate direction. In the microphone tube, quartz converts mechanical air vibrations caused by the speaker into electrical ones. Electrical vibrations in your subscriber’s handset they are converted into oscillatory ones, and, accordingly, he hears speech.

Being lattice, the crystal is faceted and each face, like a personality, is unique. If a face is densely packed in a lattice with material particles (atoms or molecules), then it is a very slowly growing face. For example, a diamond. Its faces have the shape of an octahedron, they are very densely packed with carbon atoms, and due to this they differ in both brilliance and strength.

Crystallography is not a new science. M.V. Lomonosov stands at its origins. But the cultivation artificial crystals that's a later matter. Shubnikov's popular book "The Formation of Crystals" was published in 1947. This scientific practice grew out of mineralogy, the science of crystals and amorphous solids. Growing crystals became possible thanks to the study of mineralogy data on crystal formation in natural conditions. By studying the nature of the crystals, they determined the composition from which they grew and the conditions for their growth. And now these processes are imitated, obtaining crystals with specified properties. Chemists and physicists take part in the production of crystals. If the former develop growth technology, the latter determine their properties. Can artificial crystals be distinguished from natural ones? Here's the question. Well, for example, artificial diamond is still inferior to natural diamond in quality, including in brilliance. Artificial diamonds do not evoke jewelry joy, but they are quite suitable for use in technology, and in this sense they are on an equal footing with natural ones. Again, impudent growers (the so-called chemists who grow artificial crystals) have learned to grow the finest crystalline needles with extremely high strength. This is achieved by manipulating the chemistry of the environment, temperature, pressure, and the effects of some other additional conditions. And this is already a whole art, creativity, skill - the exact sciences will not help here, they work poorly in this area. The late academician Nikolai Vasilyevich Belov said that the art of growing a crystal belongs to the specialist who has a keen sense of the crystal.

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The industrial uses of crystals are so numerous and varied that they are difficult to list. Therefore, we will limit ourselves to a few examples.

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The hardest and rarest of natural minerals is diamond. Today, a diamond is primarily a working stone, not a decoration stone. Due to its exceptional hardness, diamond plays a huge role in technology. Diamond saws are used to cut stones. A diamond saw is a large (up to 2 meters in diameter) rotating steel disk, on the edges of which cuts or notches are made. Fine diamond powder mixed with some adhesive substance is rubbed into these cuts. Such a disk, rotating at high speed, quickly saws any stone.

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Ruby and sapphire are among the most beautiful and most expensive of precious stones. All these stones have other qualities, more modest, but useful. Blood-red ruby and blue-blue sapphire are siblings; they are generally the same mineral - corundum, aluminum oxide A12O3. The difference in color arose due to very small impurities in aluminum oxide: an insignificant addition of chromium turns colorless corundum into a blood-red ruby, titanium oxide into sapphire. There are corundums of other colors. They also have a very modest, nondescript brother: brown, opaque, fine corundum - emery used to clean metal, from which sandpaper is made. Corundum with all its varieties is one of the hardest stones on Earth, the hardest after diamond. Corundum can be used to drill, grind, polish, sharpen stone and metal. Grinding wheels, whetstones, and grinding powders are made from corundum and emery.

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The new life of ruby is a laser or, as it is called in science, an optical quantum generator (OQG), a wonderful device of our days. In 1960 The first ruby laser was created. It turned out that the ruby crystal amplifies the light. The laser shines brighter than a thousand suns. A powerful laser beam with enormous power. It easily burns through sheet metal, welds metal wires, burns through metal pipes, and drills the thinnest holes in hard alloys and diamond. These functions are performed by a solid laser using ruby, garnet and neodite. In eye surgery, neodyne lasers and ruby lasers are most often used. Ground-based short-range systems often use gallium arsenide injection lasers.

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New laser crystals have also appeared: fluorite, garnets, gallium arsenide, etc. Sapphire is transparent, so plates for optical instruments are made from it. The bulk of sapphire crystals goes to the semiconductor industry. Flint, amethyst, jasper, opal, chalcedony are all varieties of quartz. Small grains of quartz form sand. And the most beautiful, most wonderful variety of quartz is rock crystal, i.e. transparent quartz crystals. Therefore, lenses, prisms and other parts of optical instruments are made from transparent quartz.

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Semiconductor devices, which revolutionized electronics, are made from crystalline substances, mainly silicon and germanium. In this case, alloying impurities that are introduced into the crystal lattice play an important role. Semiconductor diodes are used in computers and communications systems, transistors have replaced vacuum tubes in radio engineering, and solar panels placed on the outer surface of spacecraft convert solar energy into electrical energy. Semiconductors are also widely used in AC-DC converters. Crystals played an important role in many technical innovations of the 20th century. Some crystals generate an electrical charge when deformed. Their first significant application was the manufacture of radio frequency oscillators stabilized by quartz crystals. By forcing a quartz plate to vibrate in the electric field of a radio frequency oscillatory circuit, it is possible to stabilize the receiving or transmitting frequency.

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The use of artificial crystals. The world around us

Application of crystals in science and technology