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Composite materials with 83 wt.% of the 0.7Pb(Mg1/3Nb2/3)O3-0.3PbTiO3 distributed in phosphate-bonded ceramics were prepared at three different pressures. A phosphate matrix comprises a mixture of an aluminum phosphate binder and melted periclase, MgO. All samples demonstrate a homogeneous distribution of the ferroelectric perovskite phase and are thermally stable up to 900 K. At higher temperatures, the pyrochlore cubic phase forms. It has been found that the density of the composites non-monotonously depends on the pressure. The dielectric permittivity and losses substantially increase with the density of the samples. The fabricated composites demonstrate diffused ferroelectric–paraelectric transition and prominent piezoelectric properties.

The patterning of arrays of aligned multi-walled carbon nanotubes (MWCNTs) allows creating metastructures for terahertz (THz) applications. Here, the strips and columns from MWCNTs vertically grown on silicon substrates are prepared using CO2 laser treatment. The tops of the patterned arrays are flat when the laser power is between 15 and 22 W, and craters appear there with increasing power. Laser treatment does not destroy the alignment of MWCNTs while removing their poorly ordered external layers. The products of oxidative destruction of these layers deposit on the surfaces of newly produced arrays. The oxygen groups resulting from the CO2 laser treatment improve the wettability of nanotube arrays with an epoxy resin. We show that the patterned MWCNT arrays absorb the THz radiation more strongly than the as-synthesized arrays. Moreover, the pattern influences the frequency behavior of the absorbance.

The scattering theory for two crossing metallic single-walled carbon nanotubes of finite length exposed to an electromagnetic field has been developed based on a synthesis of the quantum transport formalism and classical electrodynamics. The model of the point contact has been developed to be incorporated into the Hall\'en and Pocklington equations for crossing carbon nanotubes. The influence of the contact conductance and position as well as the angle between the tube axes on the tube polarizability has been analyzed in the range of 1 GHz to 10 THz. The physical mechanisms responsible for the electromagnetic interaction between crossing tubes with zero and nonzero intertube contact conductance are shown and discussed. The influence of the coupling between the tubes on the localized plasmon resonance in them has been demonstrated.

A novel terahertz detector is here proposed, based on the use of planar arrays of graphene nanoribbons of different widths and lengths. Two distinct mechanisms are exploited to detect an external incident field: the excitation of interband transitions and of the surface plasmon polaritons resonances. The tuning of such mechanisms allows strengthening the signal, so providing an alternative solution to the problem of the low efficiency of the resonant graphene antennas. This paper proposes a possible design solution and analyzes and the feasibility of tuning the two mechanisms in the THz range.

Single layers of hexagonal two-dimensional nanostructures such as graphene, silicene, and germanene exhibit large carrier Fermi velocities and, consequently, large light-matter coupling strength making these materials promising elements for nano-optoelectronics. Although these materials are centrosymmetric, the spatial dispersion turns out to be quite large allowing the second-order noninear response of such materials to be comparable to the noncentrosymmetric 2D ones. The second-order response of massless Dirac fermions has been extensively studied, however, a general approach correct over the full Brillouin zone is lacking so far. To complete this gap, in the current paper, we develop a general quantum-mechanical theory of the in-plane second-order nonlinear response beyond the Dirac cone approximation and applicable to the full Brillouin zone of the hexagonal tight-binding nanostructures. We present explicit calculation of the nonlinear susceptibility tensor of 2D hexagonal nanostructures applicable to arbitrary three-wave mixing processes.

The project for a new injector linac for the Nuclotron–NICA accelerator tandem has been under development since 2015. The linac will accelerate protons and light ions to energies of 25 MeV and ∼7.5 MeV/nucleon, respectively. To fulfill the project, technology for fabricating superconducting RF cavities needs to be developed. The current status of the project, including the linac design, the required parameters of RF cavities, and our simulations of beam dynamics, is presented. Technological restrictions on the RF cavity parameters are discussed.

The general steps for the fabrication of a copper prototype of 325 MHz coaxial half-wave resonator (HWR) with β = 0.21 are presented and discussed in this work. The main features for the control of the electromagnetic properties during the manufacturing process of HWR are described in detail. The resonant frequency sensitivity to the accelerating gap and to the cavity height were experimentally estimated. Bead-pull measurements were performed and the electric field distribution along the beam axis of the manufactured cavity was estimated. The features of the cavity’s response in the critical coupling regime are analyzed. The experimental concept of a slow frequency tuning system (FTS) based on the moving plungers is proposed and tested. The tuning sensibility is experimentally estimated. The measured results agree with the simulations quite well, and the sensitivity for a single plunger configuration Δ f / Δ L = + 13 kHz mm−1 is achieved. The dynamic properties and operation algorithm of the FTS are studied and experimentally investigated.

A complex analysis of the dependence of the absorption coefficient of polymer composites with nonmagnetic carbon inclusions on the real and imaginary parts of the complex permittivity, as well as on the material thickness is performed in frequency range 26–37 GHz. The composites containing 0.2 wt % of carbon fibers have been obtained. It has been experimentally found that the corrugation of the composite surface substantially increases the absorbability (from 63 to 92% at a frequency of 30 GHz and a thickness of 4.50 mm) upon a decrease in the sample mass (by 28%). A method has been proposed for calculating the absorptance of corrugated composites in the microwave range.

Analysis of the electromagnetic properties of composite materials based on epoxy resin with the addition of 0.5 wt % graphene nanoplates in the frequency range of 26–37 GHz is performed. The influence of types of epoxy resin with different viscosities and the type of solvent used (ethanol, acetone) on the electromagnetic response in this frequency range are determined. It is established that the least viscous epoxy resin, Epikote 828, and solvent ethanol are most effective for creation of a shielding covering in the microwave range. Composite materials with optimal composition provide attenuation of the electromagnetic signal at a level at least 10 dB in power for a film thickness of 1.1 mm.

The present paper focuses on electromagnetic response of polymeric composites with different concentrations of multiwall carbon nanotubes in the radio (20 Hz – 1 MHz) and microwave (26–36 GHz) frequency ranges. Widely available polymeric materials, such as PVA latex (polyvinyl acetate) and styrene-acrylic copolymer, were used as a matrix. Analysis of the experimental data demonstrated that in electromagnetic shielding applications one should give preference to the styrene-acrylic copolymer, as far as application of this matrix type allows reducing the percolation threshold in such composites. As a result, it allows reaching the necessary level of shielding at a lower filler concentration, while unique properties of the chosen polymer allow expanding the range of applications for the new materials.

A novel explosive-emission cathode capable to produce high-current nanosecond electron bunches and enable tuning in terms of size is proposed and demonstrated to performance fit the particular problem. The record parameters, average diode current 6.5 kA and voltage 410 kV, are achieved by covering a conventional, planar copper cathode with a carbon film being composed of graphitic pyrolytic carbon (GrPyC). The demonstrated plasma expansion velocity and current density are comparable with those obtained with conventional graphitic cathodes. However, in contrast to purely graphite cathodes, the shape, size and surface profile of the proposed hybrid GrPyC/Cu cathodes can be readily adjusted allowing adjustments to fit requirements of a variety of high-current electronic applications.

A theoretical concept on electrodynamics of carbon nanotubes (CNTs) based on the effective two-side impedance boundary conditions for electromagnetic field is presented. The effective tensor of sheet impedance is introduced as a phenomenological parameter for single- and double-walled CNTs basing on the quantum models of charge carrier transport. Two types of boundary value problems are formulated for CNT electrodynamics: (i) eigenmodes of CNTs and (ii) CNT excitation by the external field. The second type of the problems takes into account the finite-length effects basing on the integral equation technique. These problems have been applied to the surface plasmon propagation and antenna resonances. In particular, it gives an interpretation of the terahertz conductivity peak, which physical origin has been debated by different research groups for a long time. The generalization to the quantum optical problems based on the concept of the surface noise current is given. It is applied to analysis of Purcell effect and thermal radiation in CNT.

We report on the design of highly absorptive thermostable composite materials for microwave applications. Ceramics comprising the thermostable phosphate host and silicon carbide particles or whiskers were studied in a wide frequency range from several Hertz up to microwaves. It was demonstrated that a thin layer of ceramics placed on the back-reflector absorbs perfectly at the 30 GHz frequency. In the case of a free-standing ceramic composite layer being 1 mm thick, it provides more than 50% of absorption.

Given their fascinating properties, carbon nanomaterials are currently proposed for the realization of devices working in the terahertz range, overcoming the limits of the conventional materials. Several types of devices have been proposed, designed, and theoretically studied, based on different physical phenomena observed in such materials. In this Chapter, we review the state of the art of the study on THz resonant antennas, based on features of the propagation of the surface plasmon polaritons.

The microwave conductivity and permittivity of both single-walled and multi-walled carbon nanotube (SWCNT and MWCNT) sponges were measured while compressing the samples. Compression leads to a huge variation of the absorptance, reflectance, and transmittance of the samples. The dependence of the microwave conductivity on the sponge density follows a power-law relation with exponents 1.7 ± 0.1 and 2.0 ± 0.2 for MWCNT and SWCNT sponges, respectively. These exponents can be decreased slightly by the addition of a non-conducting component which partly electrically separates adjacent tubes within the samples. The conductivity of MWCNT sponge was measured in the terahertz range while heating in air from 300 to 513 K and it increased due to an increase of a number of conducting channels in MWCNTs.

Substitutionally boron-doped multiwalled carbon nanotubes (B-CNTs) with lengths mainly less than 0.5μm and diameters 10-30 nm have been obtained by arc-discharge evaporation of the graphite anode containing boron material. The broad peak has been observed in the midinfrared conductivity spectra of the thin film comprising B-CNTs. The peak was suggested to be associated with a phenomenon known as localized plasmon resonance. Theoretical analysis has been done to confirm the possibility of this phenomenon to occur in the B-CNTs.

DC and AC electrical properties of hybrid films, consisting of carbon nanotubes and tungsten disulfide nanotubes (and fullerene like nanoparticles) were studied within the 2 ‐ 300 K temperature range and over the 20 Hz ‐ 1 MHz frequency range. The temperature dependences of the resistance R(T) exhibit behavior typical for the fluctuation-induced tunneling model in the intermediate temperature range. Analysis of the dependences of real and imaginary components of the impedance on the frequency (Z’(f) and Z”(f)) demonstrates the rising role of the contact barriers between carbon nanotubes inside hybrid films, consisting of the carbon nanotubes and inorganic tungsten disulfide nanotubes as the temperature was decreased. The active component of the impedance was found to prevail in the AC electrical properties of the hybrid films, consisting of multi-wall carbon nanotubes and WS2 nanoparticles over the entire available temperature range.

Styrene acrylate polymer (SAC) nanocomposites with various carbon nanofillers (multi-walled carbon nanotubes, MWCNT, and onion like carbons, OLCs, annealed at two different temperatures) are manufactured by means of latex based and combined routes. Concentration of the carbon nanofillers is changed in a broad interval starting from 0.01 up to 10 wt%. Elastic, dielectric, and electromagnetic interference (EMI) shielding efficiency of SAC nanocomposites are investigated. Dynamic elastic modulus, electrical conductivity, and EMI shielding efficiency of the investigated SAC nanocomposites increase along with rising nanofiller content. The effect of the addition of anisodiametric MWCNT on the elastic properties as well as EMI shielding characteristics of the SAC nanocomposites is higher than in the case of the addition of OLCs. Modification effectiveness of the polymer matrix in respects to elastic and EMI shielding performance provided by the OLC, annealed at higher temperature, is greater in comparison with the OLC, annealed at lower temperature, generally because of more perfect structure of the first. POLYM. COMPOS., 36:1048–1054, 2015. © 2015 Society of Plastics Engineers

In carbon nanotubes (CNTs) with large radii, either metallic or semiconducting, several subbands contribute to the electrical conduction, while in metallic nonarmchair nanotubes with small radii the wall curvature induces a large energy gap. In this paper, we propose a model for the signal propagation along single wall CNTs (SWCNTs) of arbitrary chirality, at microwave through terahertz frequencies, which takes into account both these characteristics in a self-consistent way. We first study an SWCNT, disregarding the wall curvature, in the frame of a semiclassical treatment based on the Boltzmann equation in the momentum-independent relaxation time approximation. It allows expressing the longitudinal dynamic conductivity in terms of the number of effective conducting channels. Next, we study the behavior of this number as the nanotube radius varies and its relation with the kinetic inductance and quantum capacitance. Furthermore, we show that the effects of the spatial dispersion are negligible in the collision dominated regimes, whereas they may be important in the collisionless regimes, giving rise to sound waves propagating with the Fermi velocity. Then, we study the effects on the electron transport of the terahertz quantum transition induced by the wall curvature by using a quantum kinetic approach. The nanotube curvature modifies the kinetic inductance and gives arise to an additional RLC branch in the equivalent circuit, related to the terahertz quantum transition. The proposed model can be used effectively for analyzing the signal propagation in complex structures composed of SWCNTs with different chirality, such as bundles of SWCNTs and multiwall CNTs, providing that the tunneling between adjacent shells may be disregarded.

This paper deals with the electrical characterization of a graphene-based material that can be proposed for realizing novel interposers to improve the electrical performance of the electronic packages. The material is a low-cost version of the graphene, realized with commercial graphene nanoplatelets, and thus potentially suitable for a large mass production. An electrical characterization of its complex permittivity in the microwave range is here provided, by using a technique based on the measurement of the scattering parameters on a microstrip-like test vehicle. A Drude model is used to retrieve the values of the equivalent complex permittivity. The results demonstrate that this material may outperform the silicon so far used for interposers.

Electrical and electromagnetic interference shielding properties of epoxy/multi-walled carbon nanotube (MWCNTs) composites are studied for low nanotube contents from 0.03 to 0.3 wt.% and different processing conditions. In situ chemical modification of carbon nanotube surfaces was achieved by ultrasonic irradiation of carbon nanotubes either in polyethylene polyamine or in liquid epoxy resin, resulting in amine-grafted or epoxy-grafted composites, respectively. Raman, TGA, and SEM analyses indicate a successful grafting of polymer chains to the nanotube surfaces. The amine-grafted MWCNT/epoxy composites show the presence of a thick polymer layer that has formed an extra phase on the carbon nanotube walls, which affects significantly the electrical conductivity and radio frequency response properties. Hence, the amine-grafted composites demonstrate a slightly higher percolation threshold (pc = 0.08 wt.%) and, at the same time, a lower absolute values of dc-conductivity as compared to that of the epoxy-grafted composites, with pc = 0.05 wt.%. In the radio frequency range, almost 3 orders of magnitude rise of the values of ac-conductivity was observed for small contents of the amine-grafted MWCNTs in epoxy. The epoxy-grafted composites could be proposed for producing effective antistatic and electrostatic dissipation coatings. Around and above the percolation threshold, the amine-grafting is critical in the radio frequency range for producing coatings with large dielectric losses. The absolute values of microwave attenuation were found to be independent of the surface modification procedure, but strongly dependent on the concentration of MWCNTs and the thickness of the composite layer.

A great progress has been achieved during last two decade in the synthesis and fabrication of different nanostructured artificial materials with fascinating mechanical, electronic and optical properties irreducible to properties of bulk media. Accompanied by the impressive parallel development of the characterization techniques and measurement instrumentation, this process necessitates the revision of traditional concepts of physics and chemistry of condensed matter, adapting them to peculiarities of the nanoworld and significantly extending our knowledge of the nature of solids and our capabilities to control their properties.

The localized plasmon resonance is studied in doped multi-walled carbon nanotubes in the high frequency terahertz range. The dependence of the resonance frequency on the tube length and chemical potential are demonstrated.

Integral equation technique of classical electrodynamics and the Landauer-Buttiker formalism of quantum transport were applied to develop electromagnetic scattering theory for a finite-length nanowire with embedded mesoscopic object. The theory is valid for a rather wide range of nanostructures, such as nanowires, nano-loops, nano-ribbons, Vivaldi antennas, etc.

The ability of graphene and other nm-thin carbon films including pyrolytic carbon (PyC) and pyrolyzed photoresist (PPF) to absorb microwave radiation is discussed. We show that being deposited on a properly chosen optically transparent dielectric substrate these films can provide more than 20 dB electromagnetic interference (EMI) shielding efficiency (SE).

Terahertz lasing by electron beam propagating over a graphene/dielectric sandwich structure is considered. A dispersion equation for the surface electromagnetic modes propagating along graphene sheets is derived and Cerenkov synchronism between surface wave and electron beam is predicted at achievable parameters of the system. The generation frequency tuning is proposed by varying the graphene doping, the number of graphene sheets, the distance between sheets, etc.

Composite materials, containing low concentrations of carbon nanotubes (CNTs) of three different diameters and heat-resistant phosphate ceramic as a matrix were prepared by cold-pressing method. Their dielectric properties were studied at room temperature in a wide frequency range (20 Hz–1 MHz). It was found experimentally and proved theoretically via modeling of the composites as a random capacitor–resistor–diode network that electrical percolation concentration depends significantly on the diameter of the nanoinclusions. The main conclusion is that the best candidate providing both the lower percolation threshold and high absolute values of ac conductivity is thinner carbon nanotubes (in our particular case, 8–15 nm).

The dielectric properties of Polymethylmetacrylate (PMMA) composites filled with CVD made multiwalled carbon nanotubes (MWCNT) of different mean outer diameters (d - 9 nm and 12-14 nm) were investigated at temperatures from 300 K to 390 K and in a wide frequency range (20 Hz-1 MHz). The percolation threshold is lower in composites with thick nanotubes. Below percolation threshold the dielectric permittivity was found also to be higher for composites with thicker carbon nanotubes. The temperature dependence of the complex dielectric permittivity of the investigated composites below percolation is mainly caused by beta relaxation in pure PMMA polymer matrix. The potential barrier for PMMA molecules rotation is higher in composites with thicker MWCNT and demonstrates non-monotonous concentration dependence.

Composite materials based on epoxy resin filled with various kinds of graphite particles: exfoliated graphite, natural graphite, and coarse, medium and fine artificial graphites have been prepared. Results of broadband dielectric investigations of such materials in wide temperature (25-450 K) and frequency (20 Hz-3 THz) ranges are presented. The dielectric permittivity strongly increases with graphite particle size. The graphite particle size and shape also have a strong impact on freezing temperature, conductivity activation energy and composite electromagnetic absorption properties at room temperature. The lowest percolation threshold is observed for exfoliated graphite (EG)-based composites. At low temperatures (below glass transition temperature of pure polymer matrix), the electrical conductivity in composites above the percolation threshold is mainly governed by electron tunnelling between graphite particles. At higher temperatures, electrical conductivity due to finite electrical conductivity of polymer matrix and by electron tunnelling from polymer matrix to graphite particles occurs in all composites. Microwave experiments show that EG is the only really effective additive, out of all investigated graphite particles, for producing electromagnetic interference shielding composite materials: 2 wt% of EG in epoxy is indeed not transparent for the electromagnetic radiation at 30 GHz.

Results of fabrication of a nanodiamond target for accelerator X-ray experiments are reported. Nanodiamond film with dimensions 5 × 7 mm and thickness of 500 nm has been made of the high pressure high temperature nanodiamonds using a filtration method. The average crystallite size of primary nanodiamond particles varies around 100 nm. Source nanodiamonds and fabricated nanodiamond film were characterized using Raman spectroscopy, electron microscopy, and X-ray diffractometry. Preliminary results show that targets made of nanodiamonds are perspective in generating crystal-assisted radiation by the relativistic charged particles, such as parametric X-rays, diffracted transition radiation, diffracted Bremsstrahlung, etc.

The results of broadband dielectric spectroscopy of onion-like carbon (OLC) based Poly(methyl methacrylate) (PMMA) composites are reported in wide temperature range 300-450 K. The dielectric properties of OLC/PMMA composites are chiefly dependent on the preparation technique, in particular annealing above the glass transition temperature of composite with 20 wt.% of OLC inclusions causes the vanishing of β relaxation, electrical conductivity appearance and onset of percolation. The percolation threshold in OLC/PMMA composites is found to be close to 20 wt.%. Below the percolation threshold the dielectric properties of composites in temperature range 300-420 K are determined mainly by β relaxation. The activation energy of such a relaxation is weakly dependent on OLC concentration.

The dielectric properties of polymethylmetacrylate (PMMA) composites filled with CVD made multiwalled carbon nanotubes (MWCNT) of different mean outer diameters (d ∼ 9 nm and 12–14 nm) were investigated in the temperature range from 300 to 420 K and in a wide frequency range (20 Hz to 1 MHz). Below the percolation threshold the temperature dependence of the complex dielectric permittivity of the investigated composites is mainly caused by β relaxation in pure PMMA matrix and the dielectric permittivity is found to be higher in composites with thicker nanotubes. The activation energy of β relaxation increases with carbon nanotube concentration. The percolation threshold is lower in composites with both thinner and oxidized carbon nanotubes. The established influence of both the MWCNT mean outer diameter and their oxidation on the broadband dielectric characteristics can be exploited for the production of effective low-cost electromagnetic and/or antistatic coatings working at different temperatures.

We report on the experimental study of electromagnetic (EM) properties of multilayered graphene in K(a)-band synthesized by catalytic chemical vapor deposition (CVD) process in between nanometrically thin Cu catalyst film and dielectric (SiO2) substrate. The quality of the produced multilayered graphene samples was monitored by Raman spectroscopy. The thickness of graphene films was controlled by atomic force microscopy (AFM) and was found to be a few nanometers (up to 5 nm). We discovered, that the fabricated graphene, being only some thousandth of skin depth, provided remarkably high EM shielding efficiency caused by absorption losses at the level of 35-43% of incident power. Being highly conductive at room temperature, multilayer graphene emerges as a promising material for manufacturing ultrathin microwave coatings to be used in aerospace applications.

This research was supported in part by the EU Horizon 2020 project H2020-MSCA-RISE-2014-644076 CoExAN and EU FP7 projects, FP7-PEOPLE-2012-IRSES-316432 QOCaN and FP7-PEOPLE-2013-IRSES-612285 CANTOR. Discussions of the basic ideas underlying this work with Dr S Starobinets and Dr D Mogilevtsev are acknowledged.

Screening effect in finite-length carbon nanotubes (CNT) and their agglomerates hinders significantly the electromagnetic interaction in composite materials. Screening effect is strong in the microwave range, and it decreases with increasing frequency resulting in a strong frequency dependence of the effective conductivity of the composite. Since screening effect is rather small in the terahertz range, the effective conductivity in this range is determined directly by the intrinsic conductivity of the inclusions. The ratio of the microwave to terahertz effective conductivities was proposed as a parameter to estimate how effectively carbon nanotube inclusions contribute to the electromagnetic performance of composite materials in the microwave range. CNT film was considered as a material where maximal possible interaction of the CNTs with EM field occurs. Single-walled CNT films and CNT-based composite materials, as well as hybrid film comprising mixtures of WS2 nanotubes and CNTs were fabricated and measured in the microwave and terahertz ranges. The electromagnetic field interaction with the inclusions has been estimated for all the samples fabricated.

This paper presents a realization of interconnects working in the THz range, based on the propagation of surface plasmonsw along carbon-based conductors, such as carbon nanotubes or graphene nanoribbons. Based on a quasi-classical transport model, the behavior of such interconnects is studied, highlighting not only the fascinating features of such realizations, but also the limiting factors due to new phenomena occurring in the THz range, such as plasmon and/or tunneling resonances. Experimental evidence of some of such phenomena is also shown.

The sponges made of multi-walled carbon nanotubes (CNT) demonstrate tunable electromagnetic response properties in the microwave range (27–36 GHz) governed by their mechanical deformation. The higher the applied stress, the denser the sponge, the more reflective it is in the Ka-band. The microwave effective conductivity of the CNT network macrostructure was proved to be linearly increased with its density.

We show that the electromagnetic coupling at the nanoscale may be accompanied by another coupling mechanism, related to quantum entanglement. Consequently, a combined "electromagnetic-quantum" coupling is created, which stipulates long-distance and long-living interactions in electric circuits. Manifestation of this effect in electromagnetic compatibility (EMC) is discussed. An efficient theoretical framework for EMC analysis in nanoelectronics is developed based on the generalized theory of electric circuits. It is shown that the action of quantum entanglement is equivalent to an addition of the supplementary elements in electric circuit with the effective admittances defined as general susceptibilities that can be calculated using the Kubo-technique.

The latest our results on triple polymer composites based on graphene nanoplatelets (GNP) covered by copper nanoparticles, iron oxide nanoparticles, and CdSe two-dimensional and spherical nanoparticles are presented and analyzed. It was found that GNP covered by copper nanoparticles results in higher conductivity and film stability increase in PEDOT:PSS than pure GNP. It was revealed that in magnetic field, composites based on GNP with iron oxide nanoparticles have metallic conductivity and form thin films with higher surface while thin films formed without magnetic field are dielectrics and have less surface. Luminescent composite based on CdSe nanoplatelets has been obtained. Two maxima in the luminescence spectra of CdSe nanoplatelets have been found and explained with a model based on efficient absorption of photons between neighbor nanoplatelets. Luminescence of active particles was different in different places of the sample and strongly depends on the graphene type. Stronger luminescence is observed in graphene with less amount of defects.

A short introduction to the electronics properties of carbon nanotubes (CNTs) is given and applied to the analysis of electric conductivity of isolated and bundled CNTs, either single-wall or multi-wall. The model of the electrical conductivity is presented in a wide frequency range, from DC to visible light. In the low-frequency range (up to the THz range), only intraband transitions are considered, whereas for higher frequencies also interband transitions are taken into account. The conductivity model is consistent with the classical Drude model and is able to describe novel phenomena associated with the signal propagation along CNTs, such as plasmon resonances of slow surface waves or intershell tunneling effect.

P.P.Kuzhir, S.A.Maksimenko, K.N.Lapko, V.A. Lomonosov, O.A.Ivashkevich, A.I.Lesnikovich, P.V.Sedyshev, V.N.Shvetsov, A.S.Kurilin, L.Sartinska, P.Silenko, G.Frolov, Yu.Solonin and S. Bellucci Research Institute for Nuclear Problems of Belarusian State University, 11, Bobruiskaya, Minsk 220030, Belarus, polina.kuzhir@gmail.com Belarusian State University, 14, Leningradskaya, 220030Minsk, Belarus Joint Institute for Nuclear Research, 6 Joliot-Curie, 141980 Dubna, Moscow region, Russia Frantsevich Institute for Problems of Materials Science, NAS of Ukraine, 3 Krzhyzhanivsky Str., 03680 Kyiv, Ukraine Frascati National Laboratory, National Institute of Nuclear Physics, Italy

Electromagnetic properties of single wall carbon nanotube (SWCNT) film on the surface of silica fibers have been studied numerically and experimentally. Optical properties of SWCNT layers are strongly influenced by the interference effects and antenna resonances in SWCNTs. Experimentally, the antenna resonances have been verified with low temperature photoconductivity measurements in terahertz range.