by Boris KOLBASOV, Cand. Sc. (Tech.), Alexander KUKUSHKIN, Cand. Sc. (Phys. & Math.); Valentin RANTSEV-KARTINOV, Cand. Sc. (Phys. & Math.), Russian Research Center "KURCHATOV INSTITUTE"; Pyotr ROMANOV, Cand. Sc. (Tech.), Federal Atomic Energy Agency

Specialists of the Russian Research Center (RRC) "KURCHATOV INSTITUTE" have made an important discovery: unusual formations produced by electric breakdowns, or discharges, in carbon-containing (carboniferous) medium. They consist of what are called base blocks of correct geometrical shape-tubules with a "cartwheel" often located at the butt, and also simple combinations of them all.

Many-sided investigations with the use of a large database created at our Center have shown that the phenomenon which interests us can also be observed in occurrences on a broad "band" or scales-from submicronic (such as dust deposits in tokamak vacuum chamber) up to galactic ones. And all of the observed phenomena share a tendency for similarity: the general structure is built up from absolutely similar "details", but of a much smaller size, and they, in their turn-from even smaller ones, etc (broadly studied now are type of structures known as fractals). Because of these properties they have been called "universal skeletal structures"*. Its elementary, or composite, "bricks" are most likely carbon nanotubes (NTs) which are well known to physicists-miniature cylinders, "rolled up" from a leaf composed of flat hexahedrons at the apexes of which there are atoms of the given substance, or material.

Researchers of the "KURCHATOV INSTITUTE" Center have taken photos of the dust particles and films (mostly carboniferous) which precipitate during an electric discharge in the tokamak T-10 vacuum chamber**. These pictures were taken with the help of transmission and scanning electron microscopes.

* See: A. Kukushkin, V. Rantsev-Kartinov, "Universal Skeletal Structures: in Lab and in... Space", Science in Russia, No. 1, 2004. - Ed.

** See: L. Golubchikov, "Tokamak-International Challenge", Science in Russia, No. 1, 2004. - Ed.

Articles in this rubric reflect the opinion of the authors. - Ed.

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The images were "processed" by the method of multi-level dynamic contrasting which helps improve by several times spatial resolution. This made it possible to distinguish in the samples skeletal structures made up of fibers: tubules (diameter 30 nm - 5 mcm), "cartwheels" (70 nm - 5 mcm) at their edge cross-section and also separately-on their own axis.

Our hypothesis is supported by the results of studies of both our domestic and foreign scientists. Thus Vladimir Stankevich, Dr. Sc. (Phys. 6 Math.) and his staff-also specialists of our Center-recently studied the aforesaid "deposits" by the method of diagnostic radiation scattering in several spectral bands. The results of these studies indicate that present in carbon films (thickness of several tens of micrometers) formed inside the tokamak chamber are the aforesaid hexahedrons consisting of carbon atoms.

It should be pointed out that from the viewpoint of an engineer and designer it is this mode of structure (from tubule base blocks with a kind of peculiar "cartwheel" at the butt) of an object make it possible to achieve the desired strength at a minimal consumption of "structural materials". As is always the case, Mother Nature took a very wise decision and we were tempted to follow her example: could we not find practical applications for the unique phenomenon-say produce a new nanomaterial on its basis.

In order to assess the reality of this idea, it is necessary first of all to try and understand the process of spontaneous assembly of the universal carcasses in the aforesaid examples, and from a greater number of nanoelements - in other words - how such carboniferous "billets" are formed? Incidentally, a certain number of them always appear in electric discharges (electric breakdowns) in the presence of graphite or organic compounds. But in the building of structural objects, such in nanoelectronic, the respective assembly techniques always require the presence of man.

Trying to answer this question, we appealed to magnetic aggregation*. It is possible that in that way they "grow up" from nanometricmicronic, and from them-macroscopic structures. The "connecting link" between these movable "skele-

* Magnetic aggregation-interconnection of particles due to mutual attraction. - Ed.

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tons" is a transverse magnetic field located inside the composite tubules. In our view, this hypothesis is confirmed by a statement recorded in 1999 - 2000 by FIAN (Physics Institute named after P. Lebedev) researchers Viktor Tserbo and Oleg Omelyanovsky, Cand. Sc. (Phys. & Math.). They demonstrated that cathode deposit particles* containing the aforesaid structures, after low-temperatures (near 4 K) temperatures in a magnetic field acquire, and even retain for 24 hours constant magnetization (which is not typical of other forms of carbon-graphite, diamond, soot). In all probability, there appears something close to high-temperature super-

* Cathode sediment is produced by electric discharge on the cathode as a result of its disintegration. - Ed.

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conductivity* in the so-called multi-bond media ("sponge" of fibers with very high electric conductivity). Indeed, discovered in the appropriate samples were very fine tubules, forming rings with the diameter of several tens of micrometer. Obviously it is through them that the induced by the trapped magnetic field and almost continuous (undamped) electric currents flow.

The results of the aforesaid studies by the FIAN experts were confirmed in the main by the experiments conducted in 2001 by staff of the Texas Center of Superconductivity Studies (Houston, USA) Dr. Zhao G. and Dr. Wang Y. S.). "Ropes" (about 100 mcm in diameter and 1 m long) consisting of "braids" of carbon nanotubes, placed into a magnetic field, demonstrated similar magnetic properties at a temperature of up to 400 K. In general, studies by Russian and American specialists have shown that energy losses of a magnetic field in the carbon nanotubes themselves and their assemblies can be anomalously low which is "on the side" of our hypothesis.

Thus, sum total of the aforesaid factors makes it possible to assume that the new nanomaterial should possess some unique properties! The known facts-mechanical super-strength of carbon nanotubes and openwork macrostructures, make it possible to expect record mechanical characteristics. The frame, or carcass itself can be formed in some medium, or, the other way round-first build it and then submerge it into this medium. And it should be noted that some technologies of production of high-strength materials, using electrophysical methods in the presence of relatively low concentrations of graphite, are "productive" exactly thanks to what we call the phenomenon of "skeletal structurization" (most probably, without the authors of such methods being aware of its role).

Another amazing property of nanomaterial stems from the proved peculiarities of separate nanotubes - tremendous electronic emission - the ability to emit electrons at heating or in the presence of an external electric field. In these conditions electrons, we know, escape from the surface of a solid body, and above all from tips on its surface. In the nanomaterial under consideration this process is boosted many times over by the unusual effectiveness and a large number of such sources. And that means that with the help of universal skeletal structures it should be quite possible to achieve unprecedented efficiency of transformation of heat into electricity (to produce powerful thermoelectric converters) and high rates of cooling of, for example, microelectronic circuits.

The openwork design of skeletal structures makes it possible to use sparingly not only one's own, but also other valuable material if it placed inside or on the surface of carbon nanotubes. It has been established that they are a reliable "storage" for some chemically active substances, such as radioisotopes. And that paves the way to the development of more "technologically effective" nuclear batteries**. And one more trend-to use the vast free surface of the skeletal for boosting the effectiveness of processes (for example, by the application of a catalyst) and in chemical and plasmo-chemical reactors. In our view, the aforesaid properties of carbon nanotubes make it possible for the carcass structures built upon them to grow and survive even in intense electromagnetic fields. And that means the reality of producing systems of electricity transmission of super-high effectiveness-with the help of HF cables on the basis of a nanomaterial of this kind.

* Superconductivity - ability of medium to acquire under certain conditions zero electric resistance (to retain electric current for any length of time after switching off of power supply). High-temperature superconductivity is observed at medium temperature much higher than 4K. - Ed.

** Nuclear battery - set of sources of electric current operating on energy of decay of radioactive elements. A miniature source of electricity. - Ed.

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