The thermostability and deformation mechanics in reinforced with graphene and silicene layered and matrix nanocomposites

V. A. Polukhin, N. A. Vatolin.

ABSTRACT:

In the present article there are under the consideration the possibilities of improving the structural and thermodynamic stabilities of metal/2D-crystal interface state, that are determined the fundamental characteristics of the layered and matrix metal/graphene and silicene nanocomposites (Me/2D-G и Me/2D-Si; Me: Al, Mg, Ir, Pd, Ru, Ni, Ti, Ag) produced by pre-operational graphene (silicene) nanoparticle dispersion or in the frame of the additive 3D typing technology (vapor-gas synthesis or CVD) with layered metal atom deposition (or as the crystalline/amorphous nanofilms) on graphene or silicene planes (1 or few lays) as substrates. The systematical analysis of the experimental available data and the original theoretical results received with combined DFT and molecular dynamics methods and concerning with nanocomposites displayed the specific structures, mechanical strength and unique electronic properties.

KEY WORDS:

2D-crystal, graphene, silicone, metallic nanofilm substrates, transition metals interatomic and electronic interaction, electronic charge doping, hybridization, sorption, interface, layered composite, reinforcing, thermostability, tensile strength, strength modulus, scanning tunneling microscopy.

Synthesis and electrochemical properties of litium vanadium bronze LixV2O5 (х = 0.1÷0.3)

М. I. Pantyukhina, P. Yu. Shevelin, Е. А. Suslov, N. N. Batalov

ABSTRACT

LixV2O5 (x = 0.1÷0.3) lithium-vanadium bronzes were synthesized by a solid-phase method and method of soft chemistry. Their electric properties were investigated. Electrochemical cycling of cells with LixV2O5 cathode and anode from the liquid and solid lithium was carried out. Lithium-vanadium bronze, obtained by method of soft chemistry were found to possess better the electrochemical characteristics than lithium-vanadium bronze, synthesized by solid-phase method.

KEY WORDS

Keywords: tlithium batteries, lithium-vanadium bronze, melt of metal lithium

Electroreduction of chromium (III) chloride and molybdenum (VI) oxide mixtures in a heat activated battery

O. V. Volkova, V. V. Zakharov

ABSTRACT

Discharge characteristics of a heat activated battery with CrCl3 –MoO3 mixtures as a cathode material is investigated. Composition and morphology of reduction products of the cathode materials have been determined. A mechanism of the reduction to metallic chromium and molibdenum has been proposed, which includes an intermediate step of melt formation of a Li3CrCl6 complex compound and lithium molybdates with LiCl.

KEY WORDS

Lithium heat activated battery, Cathode, Chromium chloride, Molybdenum oxide

Influence of non-stationary electric current on system oxide melt – gas phase

S. A. Krasikov, B. T. Utelbayev, E. N. Suleimenov

ABSTRACT

Results of studying of impact of non-stationary electric current on oxide melt are presented. It is revealed that non-stationary power inf luence can cause changing of a microstructure of liquid systems and promote improbable chemical reactions between the oxide melt and gas components. Thus division of components of a gas phase into gases – oxidizers and gases – reducers becomes very conditional. It is established that stable giving of electric current can bring system into a quasi-equilibrium state which will slow down further development of chemical reaction and directly chemical reaction can generate electric current on the course of process.

KEY WORDS

oxide melt, gas phase, non-stationary electric current, chemical reactions, microstructure

Molecular dynamics calculation of self-diffusion coefficients in molten LiF-RbBr and LiF-CsBr mixtures

M. A. Kobelev, K. I. Oleinik, A. S. Tatarinov

ABSTRACT

The self-diffusion coefficients of the ions constituting the reciprocal molten LiF-RbBr and LiF-CsBr mixtures, which are located at a temperature of 1420 K throughout the concentration range within the framework of the classical molecular dynamics method, are calculated. It is shown that the character of the microscopic motion of the fluoride ion changes qualitatively depending on the nature of the cation forming the nearest environment. Thus, in the reciprocal molten LiF-RbBr mixture at low concentrations of rubidium bromide, the nearest environment of the fluoride ion contributes to an increase in its self-diffusion coefficient, in spite of the fact that the density of the system increases.

KEY WORDS

molten alkali halides, MD simulations, self-diffusion coefficients, rigid ion model.

Electrochemical kinetics of diffusion problems with a moving phase boundary

A. V. Guntsov, N. V. Khlynova

ABSTRACT

The processes of growth and dissolution of nucleus and a film of a deposition on a solid electrode are considered. The results of solving diffusion problems on the growth and dissolution of hemispherical nuclei and a thin film of precipitate are presented. The equations of volt-ampere curves, chronoamperograms for reversible, irreversible and quasi-reversible electrode processes, ratios for the peak current, the quantity of deposition at the electrode, the peak current potential and the half-peak width of the current-voltage curve from the parameters of pre-electrolysis are given. The processes of the formation of a new phase at the solid-liquid interface, the mass-exchange processes at the electrode–low-soluble film interface, and the low-soluble film–solution boundary are discussed. The results of an experimental study of anode films are considered. There is linear dependency of the quantity of the forming compound on the electrode surface from the concentration of the ions and from the time of the pre-electrolysis in case of growing a nuclei or a thick anodic film.

KEY WORDS

electrodeposition, electrodissolution, nucleus, film, deposition, peak current, solid electrode.

Electrical conductivity and raman spectra of the α-Al2O3 – molten Li2CO3-Na2CO3-K2CO3-NaCl disperse systems

D. Zakiryanova, Е. V. Nikolaeva, А. L. Bove, B. D. Antonov.

ABSTRACT

Information on the specific electric conductivity of the dispersed system a-Al2O3-molten carbonate-chloride mixture of Li2CO3-Na2CO3-K2CO3-NaCl in the temperature range of 455–550 °C is obtained. Using the method of Raman spectroscopy, it was shown that in the investigated temperature range a-Al2O3 does not enter into a chemical interaction with the carbonate-chloride melt. Data on the strength and energy characteristics of the CO32– anion in these systems are obtained.

KEY WORDS

Conductivity, Raman spectra, disperse system, melts.

The high-volage penonena in aluminum Molten chloride electrolytes

L. A. Kazieva, S. I. Suleymanov.

ABSTRACT

The electrical conductivity of the molten chloroaluminates NaAlCl4 and KAlCl4 increases with increasing of electrical field strength and reach the limiting values (the Wien effect) which surpass their usual low-voltage conductivity up to 200 and 700 percent respectively. These results have been obtained on the base of analysis of the microsecond high-voltage discharges in the melts (the Wien effect). After the high-voltage pulses discharges having been completed in the melts, their conductivity and electrolyze current have been found to rise up to 50% and their decomposition potentials has found to decrease more than 20% (the “memory effect”). The relaxation time of a non-equilibrium state reaches 5 minutes and more.
KEY WORDS

activation, melts, chloroaluminates, Wine effect, relaxation, structure, aluminum, conductivity.

Determination of synthesis modes of powder intermetallic compound of composition Co2Er in halogenide melt.

D. A. Kondratyev, I. V. Tolstobrov, A. N. Bushuev, O. V. El’kin, O. S. Bervickaya, O. V. Chernova.

ABSTRACT

The present study examines the synthesis capacity of powdered Co2Er intermetallic compound in molten eutectic Lithium- Potassium Chlorides mix at constant temperature of 850K when using no-current diffusion saturation technique.

Based on the obtained results, the synthesis modes for the specified composition of powdered Co2Er intermetallic compound were derived. The components’ composition ratio of the reaction mix for the metal phase was established, at which point the synthesis of the specified powdered compound could still be possible. In this case, the powdered compound did not contain admixtures of both the other-phase intermetallic compounds and the unreacted metal substrate powder (Co).
The credibility of the obtained findings was confirmed through X-ray fluorescence and X-ray diffraction analyses using the EDX‑720 energy dispersion X-ray fluorescence spectrometer along with the XDR‑7000S X-ray powder diffractometer.

KEY WORDS

powder alloy, intermetallic compound, cobalt, erbium, permanent magnet, diffusion saturation, non-current transfer, expanded salt mixture, phase, Co2Er.

Physicochemical foundations for the synthesis of zinc oxide in molten chlorides

T. A. Rozdjalovskaja.

ABSTRACT

The results of the investigation of chloride ions oxidation during the oxygen bubbling through zinc and alkali metal (Na, K) chloride melts at 600 °C are presented. The amount of gaseous chlorine produced depends on the molar ratio of chlorides in the mixture. It is shown that the amount of released chlorine is directly proportional to the values of the effective polarizing force of the cations. The kinetic characteristics of chlorine formation were determined and calculated: the reaction order, reaction rate constants, and the activation energy values. Particle size, chemical composition, and surface area for some samples of ZnO were determined.

KEY WORDS

zinc and alkali metals chloride melts, zinc oxide production, molten chlorides oxidation.