Erratum to: Several Articles in JETP Letters Published Online First

JETP Letters - An Erratum to this paper has been published: https://doi.org/10.1134/S0021364022330013     

Dendrite structure of electrolytic gold deposited from molten chlorides

The structure of gold deposits produced by electrolysis of molten eutectic NaCl-KCl-CsCl at 500–700°C in an inert atmosphere is studied. The initial process on the gold cathode is the epitaxial growth of a layer up to 3 μm thick with a smoothed surface and a considerably later growth of grain boundaries. Gradually, on the protruding parts of deposit, the growth of dendrites starts. The dendrites are the major form of gold deposits. Typical gold dendrites are two-dimensional 2D〈112〉 and 2D〈112〉–〈110〉 and three-dimensional 3D〈100〉. Upon supplying air into the atmosphere above the melt at high current densities at the initial period there appears a powder comprising particles of a rounded twisted shape. Probable mechanisms leading to the formation of the “rounded” powder are discussed.     

Behavior of nanosized tungsten oxide bronzes produced by high-temperature electrolysis in model processes of desulfurization of petroleum products

Tungsten oxide bronzes were produced by an original method of high-temperature electrochemical deposition. Their catalytic properties in a model process of desulfurization of petroleum products-benzothiophene peroxidation were studied. The effect of the particle size on the catalytic and catalase activity of samples was shown.     

Three-dimensional nucleation and growth under galvanostatic conditions

The nucleation and growth of new phase clusters have been studied under galvanostatic conditions. Time dependences of the overpotential, number, and size of clusters formed on the electrode have been calculated from a model of the electrocrystallization process.     

Torsional waves of finite amplitude in elastic rod

We propose mathematical models generalizing the Coulomb and Vlasov equations of torsional vibrations of rods by taking the geometric nonlinearity into account. In the general case, the nonlinearity is taken into account both in the system of displacements (because the displacement vector in the case of rod torsion can be finite even for small strains) and in the relations between displacements and strains. We analyze nonlinear torsional stationary waves and find the effect of splitting of soliton-like unipolar waves in countercollisions. We also show that, in several cases, the existence of nonlinearities can also induce dispersion and that nonlinear stationary waves can also exist in the absence of dispersion in the linear medium.     

First Experimental Synthesis of Mg Orthocarbonate by the MgCO3 + MgO = Mg2CO4 Reaction at Pressures of the Earth’s Lower Mantle

JETP Letters - Mg-carbonate is one of the main carbonates subducting from the Earth’s surface into the mantle and possible reactions of this compound with the main mantle minerals determine...     

Catalase activity of coarse-grained and nanosized oxide tungsten bronzes obtained by electrolysis of molten salts

Nanocrystalline samples of K _x Li _y WO₃ with hexagonal structure obtained by electrodeposition of molten salts were several times more active in catalytic decomposition than the coarse-grained materials.     

Diffusion Coefficients for Gold and Silver Ions in NaCl–KCl–CsCl Eutectic Melt

Diffusion coefficients for gold and silver ions are measured by the chronopotentiometry method at 500–700°C. At 500–550°C, the former are higher than the latter. The coefficients fit a straight line in the log Dvs. 1/Tcoordinates. The results are explained in terms of the translation and hopping diffusion mechanisms.     

On the theory of cyclic voltammetry for formation and growth of single metal cluster

The theory of cyclic voltammetry for formation and growth of single metal cluster has been developed. The analytical expressions for cyclic voltammograms and the overpotential dependences of the cluster size have been obtained. The applicability of this theory was discussed.     

Nucleation of Gold Crystals during Electrolysis of Chloride Melts

Effect of electrodeposition conditions on the nucleation of gold crystals at a glassy-carbon cathode in an NaCl–KCl–CsCl melt at 500–700°C is studied by a galvanostatic technique. The maximum nucleation overvoltage can reach 550 mV. At low current densities, the surface of glassy carbon undergoes activation due to spontaneous deposition of gold crystals. The overvoltage vs. time curve for a melt containing an elevated (as compared with equilibrium) amount of chlorine exhibits additional wave that precedes the nucleation peak. The wave is probably connected with the recharge of ions of Au(III) to Au(I). The oxide film disappears from the cathode surface, thus facilitating the nucleation process. On a modeling electrode with a current leakage, an increase in the maximum overvoltage is discovered, which is not connected with the cathode activation. Exchange currents for the discharge-ionization of gold at the growing nuclei are estimated.