Nanocarbons And Quantum Dots Formation In New Hybrid Materials

We present technique of obtaining complex hybrid structures combining the multi-walled carbon nanotubes or multi-layer graphene and luminescent hydrophobic semiconductor core/shell quantum dots CdSe/ZnS. As a result, a formation of quantum dot decorated carbon nanotubes and graphene films is evidenced by 2D microluminescence and micro-Raman mapping of quantum dots and nanocarbons, respectively, where a spatial correlation between the luminescence and Raman signals is found. © 2014 SPIE.912612-02-00938; RFBR; Russian Foundation for Basic Research; 12-02-01263; RFBR; Russian Foundation for Basic ResearchKalantar-Zadeh, K., (2008) Nanotechnology-Enabled Sensors, p. 490. , K. Kalantar-zadeh, B. Fry. New York.: Springer Science & Business Media(1955) Springer Handbook of Nanotechnology, , Ed. B. Bhusha.-New York.: Springer Science & Business Media, 2010, ISBN: 978-3-642-02524-2Cattanach, K., Kulkarni, R.D., Kozlov, M., Manohar, S.K., Flexible carbon nanotube sensors for nerve agent simulants (2006) Nanotechnology, 17, pp. 4123-4128Peng, S., O'Keeffe, J., Wei, C., Cho, K., Kong, J., Chen, R., Franklin, N., Dai, H., Carbon nanotube chemical and mechanical sensors (2001) Proceedings of the 3rd International Workshop on Structural Health Monitoring, pp. 1-8. , USA, September 17-19, 2001, Stanford University, StanfordSnow, E.S., Perkins, F.K., Houser, E.H., Badescu, S.C., Reinecke, T.L., (2005) Science, 307, pp. 1942-1945. , Chemical detection with a single-walled carbon nanotube capacitorStar, A., Joshi, V., Skarupo, S., Thomas, D., Gabriel, J.-C.P., Gas sensor array based on metal-decorated carbon nanotubes (2006) J. Phys. Chem. B, 110, pp. 21014-21020Xu, Z., Gao, H., Guoxin, H., Solution-based synthesis and characterization of a silver nanoparticle-graphene hybrid film Carbon, 49 (14), pp. 4731-4738Cao, A., Liu, Z., Chu, S., Wu, M., Ye, Z., Cai, Z., Chang, Y., Liu, Y., A facile one-step method to produce graphene-cds quantum dot nanocomposites as promising optoelectronic materials (2010) Adv. Mater, 22, pp. 103-106Yang, Y.-K., He, Ch.-E., He, W.-J., Yu, L.-J., Peng, R.-G., Xie, X.-L., Wang, X.-B., Mai, Y.-W., Reduction of silver nanoparticles onto graphene oxide nanosheets with N,Ndimethylformamide and SERS activities of GO/Ag composites (2011) J Nanopart. Res, 13, pp. 5571-5581Lightcap, V., Kamat, P.V., Fortification of cdse quantum dots with graphene oxide. Excited state interactions and light energy conversion (2012) J. Am. Chem. Soc, 134, pp. 7109-7116Ghosh, A., Rao, K.V., Voggu, R., George, S.J., Non-covalent functionalization, solubilization of graphene and single-walled carbon nanotubes with aromatic donor and acceptor molecules (2010) Chemical Physics Letters, 488, pp. 198-201Kim, Y.-T., Han, J.H., Hong, B.H., Kwon, Y.-U., Electrochemical synthesis of cdse quantum-dot arrays on a graphene basal plane using mesoporous silica thin-film templates (2010) Adv. Mater, 22, pp. 515-518Konstantatos, G., Badioli, M., Gaudreau, L., Osmond, J., Bernechea, M., Arquer De Garcia, F.P., Gatti, F., Koppens, L.F.H., Hybrid graphene-quantum dot phototransistors with ultrahigh gain (2012) Nature Nanotechnology, 7, pp. 363-368Wang, Y., Yao, H.-B., Wang, X.-H., Yu, Sh.-H., One-pot facile decoration of CdSe quantum dots on graphene nanosheets: Novel graphene-CdSe nanocomposites with tunable fluorescent properties (2011) J. Mater. Chem, 21, pp. 562-566Murray, C.B., Gaschler, W., Sun, S., Doyle, H., Betley, T.A., Kagan, C.R., Colloidal synthesis of nanocrystals and nanocrystal superlattices IBM J. Res. & Dev., 45 (1), pp. 47-56Ermakov, V.A., Alaferdov, A.V., Vaz, A.R., Baranov, A.V., Moshkalev, S.A., Nonlocal laser annealing to improve thermal contacts between multi-layer graphene and metals (2013) Nanotechnology, 24 (15), p. 15530110Bogdanov, K., Fedorov, A., Osipov, V., Enoki, T., Takai, K., Hayashi, T., Ermakov, V., Moshkalev A, S., Annealing-induced structural changes of carbon onions: High-resolution transmission electron microscopy and Raman studies Baranov Carbon, , 02/201

ESTIMATION OF PREDICTION EFFICIENCY OF SEISMIC REGIME PROBABILISTIC MODEL PARAMETERS

On the basis of theoretical-probabilistic approach to the Kamchatka earthquakes catalog the subset of random events was specified and their probabilities were calculated. The received probabilities of random events considered as predictors of strong earthquakes with energy class KS 14. Their effectiveness V, reliability R and prediction efficiency (informative) J were calculated for periods of seismic activity and seismic calm

Perspective Method of Betavoltaic Converter Creation

Some results on planar diode structure creation by the method of a plasma-immersion ion implantation is presented in this paper. Obtained leakage current ~ 1 uA/cm2 at reverse voltage – 1 V. The cryogenic plasmochemical silicon etching process is developed, able to form the structured silicon layer with system of deep holes with high aspect ratio

Characteristics of ADS target irradiated by 200…400 MeV proton beam

The problems of target choice for compact ADS with reactor thermal power 200…400 MW and 200…400 MeV proton beam are considered. Simulation results of neutron yield from fissile and non-fissile targets are presented and the optimal target sizes are calculated. The principal target design characteristics and its thermal condition are also considered.Рассмотрены вопросы выбора мишени для компактной электроядерной установки с мощностью реактора 200…400 МВт и энергией протонов 200…400 МэВ. Представлены результаты моделирования выходов нейтронов из размножающих и неразмножающих мишеней и определены оптимальные размеры мишени. Рассмотрены особенности конструкции мишени и вопросы ее температурного состояния.Розглянуто питання вибору мішені для компактної електроядерної установки з потужністю реактора 200…400 МВт і енергією протонів 200…400 МеВ. Представлено результати моделювання виходів нейтронів із розмножуючих і нерозмножуючих мішеней та визначені оптимальні розміри мішені. Розглянуто особли-вості конструкції мішені і питання її температурного стану

Excitation of surface plasmon waves with a nanoantenna: simple analytical solution and its numerical verification

В работе предлагается простой аналитический метод решения задачи о возбуждении поверхностных плазмон-поляритонов металлической наноантенной, расположенной вблизи поверхности металла. Метод основан на теореме взаимности и аналогичен нахождению амплитуд мод диэлектрических волноводов, возбуждаемых источниками тока. Для большей наглядности предлагаемый подход демонстрируется на примере наиболее простой двухмерной геометрии. Справедливость аналитического решения подтверждается результатами численного моделирования методами конечных разностей и конечных элементов. In this work, we demonstrate a simple analytical approach to the problem of surface plasmon polaritons excitation with a metallic nanoantenna placed above a metal surface. The method uses the reciprocity theorem and is similar to the calculation of amplitudes of dielectric waveguide modes excited by a current distribution. To maximize clarity of the demonstration, we formulate the problem in a simple two-dimensional geometry. The analytical results are shown to agree well with the numerical solution obtained by finite elements in frequency domain and finite difference in time domain methods.Работа выполнена при поддержке Российского фонда фундаментальных исследований (грант №20-02-00556А)

Interplay of Electron-Phonon Interaction and Electron Correlation in High Temperature Superconductivity

We study the electron-phonon interaction in the strongly correlated superconducting cuprates. Two types of the electron-phonon interactions are introduced in the $t-J$ model; the diagonal and off-diagonal interactions which modify the formation energy of the Zhang-Rice singlet and its transfer integral, respectively. The characteristic phonon-momentum $(\vec q)$ and electron-momentum $(\vec k)$ dependence resulted from the off-diagonal coupling can explain a variety of experiments. The vertex correction for the electron-phonon interaction is formulated in the SU(2) slave-boson theory by taking into account the collective modes in the superconducting ground states. It is shown that the vertex correction enhances the attractive potential for the d-wave paring mediated by phonon with $\vec q=(\pi(1-\delta), 0)$ around $\delta \cong 0.3$ which corresponds to the half-breathing mode of the oxygen motion.Comment: 14 pages, 13 figure

Optical symmetries and anisotropic transport in high-Tc superconductors

A simple symmetry analysis of in-plane and out-of-plane transport in a family of high temperature superconductors is presented. It is shown that generalized scaling relations exist between the low frequency electronic Raman response and the low frequency in-plane and out-of-plane conductivities in both the normal and superconducting states of the cuprates. Specifically, for both the normal and superconducting state, the temperature dependence of the low frequency $B_{1g}$ Raman slope scales with the $c-$axis conductivity, while the $B_{2g}$ Raman slope scales with the in-plane conductivity. Comparison with experiments in the normal state of Bi-2212 and Y-123 imply that the nodal transport is largely doping independent and metallic, while transport near the BZ axes is governed by a quantum critical point near doping $p\sim 0.22$ holes per CuO$_{2}$ plaquette. Important differences for La-214 are discussed. It is also shown that the $c-$ axis conductivity rise for $T\ll T_{c}$ is a consequence of partial conservation of in-plane momentum for out-of-plane transport.Comment: 16 pages, 8 Figures (3 pages added, new discussion on pseudogap and charge ordering in La214

Flux Phase as a Dynamic Jahn-Teller Phase: Berryonic Matter in the Cuprates?

There is considerable evidence for some form of charge ordering on the hole-doped stripes in the cuprates, mainly associated with the low-temperature tetragonal phase, but with some evidence for either charge density waves or a flux phase, which is a form of dynamic charge-density wave. These three states form a pseudospin triplet, demonstrating a close connection with the E X e dynamic Jahn-Teller effect, suggesting that the cuprates constitute a form of Berryonic matter. This in turn suggests a new model for the dynamic Jahn-Teller effect as a form of flux phase. A simple model of the Cu-O bond stretching phonons allows an estimate of electron-phonon coupling for these modes, explaining why the half breathing mode softens so much more than the full oxygen breathing mode. The anomalous properties of $O^{2-}$ provide a coupling (correlated hopping) which acts to stabilize density wave phases.Comment: Major Revisions: includes comparisons with specific cuprate phonon modes, 16 eps figures, revte