I. V. Osipova

Effect of electrode material on impedance spectra of metal-polyethylene structures with carbon nanotubes

The effect of an electrode material on electrical properties of a composite material based on super-high-molecular polyethylene (SHMPE) filled with carbon nanotubes has been studied using impedance spectroscopy. Using the method of replacing the sample by an equivalent electric circuit, it has been found that, depending on the electrode material, a blocking barrier with high active resistance and a space charge region adjacent to it arise in the interface region. It has been shown that the barrier height is controlled by surface electronic states of SHMPE and weakly depends on the electron work function of metal electrodes (Bardeen barrier). The characteristic times of electrical relaxation characterizing bulk and interface regions of the composite under study have been determined.

Nickel-containing carbon nanotubes and nanoparticles prepared in a high-frequency arc plasma

This paper presents the results of an investigation of nickel-containing carbon nanostructures prepared by plasma-chemical synthesis in a carbon-helium plasma jet at atmospheric pressure with the arc fed by a high-frequency current. It is demonstrated that, under these conditions, the conversion of graphite into a carbon condensate reaches 98 wt % and the contents of carbon nanotubes and nickel in this condensate are 72 and 10 wt %, respectively. Sequential treatment with nitric and hydrochloric acids has made it possible to extract purified carbon nanotubes and nickel nanoparticles coated with a carbon shell (approximately 50 nm thick) in which the nickel content is 4 wt %. Data are presented on the diameters of the prepared nanotubes and on the state of carbon in the samples.

Preparation and investigation of the composite based on superhigh-molecular poly(ethylene) and WO3

A composite based on superhigh-molecular poly(ethylene) and tungsten trioxide nanoparticles has been synthesized using the activation method. Tungsten nanoparticles have been prepared using the plasmachemical method and then oxidized in air. The particle size is 48 ± 7 nm. It has been established that the addition of tungsten nanoparticles to superhigh-molecular poly(ethylene) brings about changes in the arrangement of hydrocarbon chains in the structure, which leads to an improvement of the strength characteristics of the products.

Synthesis and investigation of iron fullerene clusters

Iron fullerene clusters are prepared by plasma chemical synthesis and investigated using electron magnetic resonance. It is shown that these clusters can be prepared both by plasma chemical synthesis of fullerenes with iron and by mixing of a fullerene solution with a powder of iron nanoparticles coated with carbon shells. A liquid chromatographic technique is proposed for separating iron fullerence clusters.

The Technology and Setup for High-Throughput Synthesis of Endohedral Metal Fullerenes

The article presented the technology and setup for high-throughput synthesis of carbon nanostructures. It was shown that the plasma-chemical synthesis of fullerenes and endohedral metallofullerenes (EMF) in high-frequency arc discharge can be controlled by changing helium pressure in the chamber. The methods of extraction using Lewis acids and separation of individual EMF by HPLC were suggested as the most effective.

Nanodispersed Powders of Fe-Ni Particles with Carbon Shell

УДК 539.2:533.9(07) Nanodispersed Powders of Fe-Ni Particles with Carbon Shell Grigory N. Churilov,∗ Natalia G.Vnukova Kirensky Institute of Physics Federal Research Center KSC SB RAS Akademgorodok, 50/38, Krasnoyarsk, 660036 Siberian Federal University Svobodny, 79, Krasnoyarsk, 660041 Russia Nikita S. Nikolaev† Siberian Federal University Svobodny, 79, Krasnoyarsk, 660041 Russia Gari A. Glushenko, Irina V. Osipova, Vladislav A. Lopatin Sergey V.Komogortsev, Dmitry A.Velikanov Mikhail N. Volochaev‡ Kirensky Institute of Physics Federal Research Center KSC SB RAS Akademgorodok, 50/38, Krasnoyarsk, 660036 Russia Ivan V. Nemtsev§ Krasnoyarsk Scientific center SB RAS Akademgorodok, 50, Krasnoyarsk, 660036 Russia

Synthesis of 6H-SiC single-crystal nanowires in a flow of carbon-silicon high-frequency arc plasma

Silicon carbide 6H-SiC nanoparticles and nanowires were obtained in carbon-silicon high-frequency arc plasma plasma in a helium atmosphere at a pressure of 0.1–0.6 MPa. It was shown that 6H-SiC nanowires grow from the arc plasma, as well as from the vapor, according to the known mechanism of vapor-solid condensation on a cold surface covered with single-crystal silicon carbide nuclei. The content of silicon carbide nanowires in the condensate reached 60 wt %. The obtained single-crystal silicon 6H-SiC nanowires had the diameter of 15–18 nm and length of 200–600 nm.

Spectral characteristics of a 44-kHz arc discharge excited in an atmospheric-pressure argon flow

Results are presented from experimental studies of an ac (44-kHz) arc discharge excited in an atmospheric-pressure argon jet between two copper electrodes. The first (central) electrode is a water-cooled rod with an axial opening for argon injection, while the second electrode is a loop of a tube lying in a plane perpendicular to the axis of the central electrode. The argon radiation spectra are measured, and the characteristic intensity profiles of the spectral lines as functions of the distance from the end of the central electrode are determined. All the observed transitions in the 245-to 370-nm wavelength range are identified.