Basic directions and results of studies

Staff of the Laboratory is involved in research of nanocarbon materials since 1995. In 1997, Russia's first instrument for the arc synthesis of single-walled carbon nanotubes (SWCN) was constructed and put into operation. Since then, carbon nanotubes have become the main focus of laboratory researches. In 2003, the possibilities for the synthesis of carbon nanotubes increased from the launch of the second installation for the synthesis of films of single-walled carbon nanotubes on different substrates from various carbon-containing gases and vapors of alcohol. The results were interesting, shedding light on the mechanisms of growth of single-walled carbon nanotubes on catalytic metal particles and double-walled carbon nanotubes.

The main analytical method for the laboratory is optical spectroscopy: Raman scattering and optical absorption of light in a broad spectral range. There have been new results on selective diameter nanotubes resonant Raman scattering of light. Computer simulation of the electronic structure of nanotubes, based on "folding" of the Brillouin zone, allowed interpreting the switching of dominant mode in contour of "breathing" Raman modes of the nanotubes depending on the photon energy of the exciting laser radiation. Heat-induced changes in the Raman spectra of the SWNT were detected during heating in the laser beam and in the furnace. The threshold temperature of carbon nanotubes oxidation was dependent on its diameter. Observation of the disappearance of "breathing" Raman modes allowed to determine the threshold temperature for the oxidation of nanotubes of different diameters. Studies have been conducted using the Raman spectroscopy in a diamond high-pressure cell and obtained interesting results concerning the transformation of the structure of carbon nanotubes under pressure. The narrowing of the band gap of semiconducting nanotubes under pressure was found.

Since 2003 the staff of the laboratory started working with suspensions of carbon nanotubes using ultrasonic treatment and ultracentrifugation for their preparation. Optical absorption spectra of individual nanotubes and luminescence spectra were first obtained for nanotubes synthesized by arc method. In 2004, the laboratory has been involved in experiments to study nonlinear optical properties of suspensions of nanotubes. They were first used as a saturable absorber in the cavities of different lasers (laser on Er3 +-glass, F2 -: LiF laser, etc.) In all cases, the regime was implemented passive Q-switching. The results confirmed the promise of suspensions of nanotubes for ultra-fast modulation of light beams.

In 2006, work began on the use of nonlinear optical elements based on single-walled carbon nanotubes in fiber lasers. To achieve this, the technology for production of thin polymer films of optical quality with uniformly distributed nanotubes. Films were comprehensively characterized by optical spectroscopy. The first results of passive mode locking in fiber lasers for Er3 + - glass.

Actively developed as other promising areas of application of single-walled carbon nanotubes - Vacuum Electronics. Demonstrated that carbon nanotubes and nanostructures based on them are effective low-field electron emitter, and can be used as cathodes in tubes, digital indicators, displays. A laboratory prototypes of such devices were created.

Awards

Presidential grant for young scientists - Ph.D. A.V. Osadchy, S.N. Bokova.

International Competition of Scientific Papers for Young Researchers in Nanotechnology II place - N.R. Arutyunyan

International Competition of Scientific Papers for Young Researchers in Nanotechnology III place - M.S. Komlenok

Prize for the poster at the European Materials Research Society (EMRS 09) - A.I. Chernov

Grant UMNIK - students A. Orlov, M. Nikitin, E. Diryugina

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