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What we call science, or studies of materials are on the brink of a scientific revolution which has been ushered in by the unprecedented progress in physics, chemistry and biology in the latter half of the 20th century.
As we remember, following the "met-aUurgjcalboom" of the 1930s and 1940s and the breakthroughs in the development of semiconductors (1950s-1960s) which brought about the computer revolution, scientists focused their attention on bioorganics and nanotechnologies. This was followed by the use of synchrotrons in studies of materials. These studies pave the way for the development of materials of a new generation, and are backed by subsidies of billions of dollars provided by the governments of many countries.
An interesting view on this field of scientific and technological progress has been expressed by Alexander Shubnikov, Corresponding Member of the Russian Academy of Sciences, Director of the Institute of Crystallography named after Shubnikov (IKAN), in an article published in the EXPERT journal.
In his view a powerful impetus for a breakthrough in this field of modern research has been provided by radio communications and radiology. As early as in the 1930s and 1940s Academician Shubnikov, an outstanding Soviet physicist and crystallographer, carried out studies on piezoeffect in crystals. At first sight the phenomenon looks fairly simple. When a crystal is compressed along one of its axes an electric charge is produced upon it. And the other way round-when an electric field is applied to a crystal it undergoes deformation. These abstract results of experiments generated some very practical results: it turned out that the above piezoeffect can provide the basis for the whole of radio communications and radar technology.
When Acad. Shubnikov published his results, they received a high assessment of the Soviet military experts who began building an infrastructure for the development of this branch of research. The academic Institute of Crystallography opened at that time was an important core of that effort. Set up there almost at once was a specialized lab of applied research investigating the use of crystals in radio communication. Institute experts studied simultaneously the processes of formation of crystals, their structure and properties and tried to produce man-made piezocrystals in lab, instead of looking for them in nature.
Acad. Kovalchuk points out in his article that crystallography in general originated from pure mineralogy and geology. At first crystals were assessed in simple terms: whether they are transparent or not, measuring the angles between facets and even tasting them. This was followed by chemical analyses for assessing the "menu" of the substances involved and understanding the mechanisms which bind them together. In this way crystallography was amalgamated with chemistry.
For studies of the physical properties of crystals it was necessary to see their structure at atomic resolution. Further studies, above all the application of X-ray structural analysis, turned crystallography into an independent branch of physics.
Today it is actively invading biology. The first steps were made in the 1960s and 1970s when scientists discovered the DNA twin spiral, the structures of many proteins and when physics found its way into molecular biology through X-ray structural analysis. As a result, scientists were able to observe how the "smooth" progressing of bioorganic materials studies gave way to its tempestuous growth.
Today IKAN is directly related to research in biotechnology. First-its scientists have been investigating for several decades atomic structure of proteins and nuclein acids and have developed a national school of X-ray structural analysis of biological molecules. Second, our specialists have learned to join together in a certain way atoms and molecules and obtain sets of artificially synthesized organic and inorganic substances, like all sorts of crystals, polymers and even protein molecules. And the decoding of their atomic-molecular structure has provided the foundation for a range of modern technologies.
Over the 50 years of their development material studies of semiconductors have arrived at two basic methodological principles. First, the use of molecular-ray epitaxy * ; with its help one can "build" any structure (such as supergrip) layer by layer and alternating the sources of certain ions and atoms. Second, one can use quantum points appearing in crystals (this is based on the principle of self- organization upon which the living nature is based). And when researchers learned how to "play"
* Epitaxy - the growth on a crystalline substrate of crystalline substance that mimics the orientation of the substrate. - Ed.
with separate atoms and molecules, that is operate at the nanometric level and with nanotechnologies, they began to design artificial materials: semiconductor structures, organic molecule-polymers (like synthetic rubber and many other things). And different variations are also possible with proteins.
Acad. Kovalchuk also points out that the diversity and the "design" possibilities in organics are greater by an order of magnitude than in inorganics, and by way of self- organization it is possible to produce any organic or hybrid structures. On the basis of nanostudies and nanoparameters there occurs what we call a unique methodological rapprochement of the sciences concerning the organic and inorganic nature. But in order to deal with nanotechnologies in a practical way one has to have at his disposal a serious research potential backed by an arsenal of research equipment. At this particular level Russia has quite enough at its disposal, including, above all, electron microscopes with atomic resolution which makes it possible for the ressearcher to see the lattice directly, such as rows of atoms with their defects, etc. Second, this is what we call atomic-force, or tunnel microscopy which makes it possible to examine atomic relief and structure by contact or con-tactless methods, while simultaneously manipulating atoms, shifting them along the surface-doing what one could call a kind of nanolithography.
Incidentally, an effective tool that can be used for nanodiagnostics is an electron accelerator-synchrotron. With its help researchers can accelerate a beam of particles to tremendous velocities before it hits the target which "falls apart". This is registered by the detector and the specialists then determine what kind of particles are thus produced. This is a simplified model of a nuclear-physical experiment on the basis of an accelerator. But should it be necessary to accelerate the particles to even greater velocities, increased energy spendings fail to produce the expected results and the cause of that is the parasitic bremsstrahlung which possesses some unique properties. First, it has a continuous spectrum: infrared, visible light, then deep vacuum ultraviolet, ultrasoft X-rays, soft X-rays, hard X-rays and gamma-rays-everything which is used for diagnostics. The second factor is brightness. For example, the X-ray spectrum of synchrotron emission is eight to ten orders of magnitude brighter than the radiation of the existing laboratory X-ray tubes. And synchrotrons of the third and fourth generations produce brightness which is 16 to 19 orders of magnitude greater and experts say it can be brought up by more than 20 orders of magnitude. Emissions of this kind possess a high degree of natural collimation - the beam of particles does not scatter over distances of tens of kilometers even when passing through the atmosphere.
All of the aforesaid properties of synchrotron radiation, backed by the achievements of X-ray diffraction studies (including those conducted at IKAN) warrant calling the current period a "renaissance" of X-ray physics. And it turns out that the synchrotron is a unique research tool for the whole of nanodiagnostics. Today all sorts of emissions experiments-optical, X-ray and infrared-can be staged at one and the same place-the site of an accelerator. And we do have the appropriate facilities here in Russia. For example, IKAN researchers are making good use of the recently commissioned (the first of its kind in this country) source of synchrotron radiation located at the "Kurchatovsky Institute" research center.
Summing it up, nanotechnologies represent an area of knowledge in which Russia possesses serious competitive advantages.
M. Kovalchuk, "Line of Synthesis", EXPERT journal, No. 13, 2003
Prepared by Yaroslav RENKAS
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