Olga V. Grishenkova

Galvanostatic nucleation and growth under diffusion control

A theory is proposed for galvanostatic three-dimensional nucleation and growth of new phase clusters controlled by diffusion of depositing ions in the bulk of the electrolyte to the clusters surface. The mathematical model is used to calculate the time dependences of the overpotential, number, and size of clusters formed on the electrode.

Galvanostatic phase formation

The results of a theoretical study on initial stages of electrodeposition under galvanostatic conditions are presented. The model of three-dimensional nucleation and growth under these conditions is developed. This model is used to calculate the times dependences of the overpotential, number of clusters formed on the electrode, and nucleation rate. The peculiarities of nucleation and growth kinetics are analyzed.

Electrochemical nucleation and growth of silicon in the KF-KCl-K2SiF6 melt

The work related to the study of the initial stages of the silicon electrodeposition on the glassy carbon electrode in molten KF-KCl-K2SiF6 was performed. The silicon nucleation and growth process was investigated using cyclic voltammetry, chronoamperometry, and scanning electron microscopy. It was shown that the electrocrystallization process occurs by the instantaneous nucleation with diffusion-controlled growth under the studied conditions. The Scharifker-Hills theoretical model was used to calculate the nucleation density and the diffusion coefficient of depositing ions.

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.

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.

Simulation of the potentiodynamic and galvanostatic phase formation in melts

A general scheme is used to consider the initial stages of electrocrystallization under potentiodynamic and galvanostatic conditions. Proposed theoretical models are shown to agree well with the experimental results obtained during the electrodeposition of silver crystals on an iridium microelectrode from nitrate melt containing an excess background electrolyte.

Nucleation and growth of metal nanocrystals during electrocrystallization in melts

The initial stages of electrocrystallization in melts are considered. The nucleation and growth rates of metal nanocrystals during electrodeposition are calculated. The diffusion coefficients in the size space in the Fokker–Planck equation, which describes phase formation, are found. The method of calculating the number of nanoclusters formed on an electrode has been proposed. The concentration dependence of the phase formation under potentiostatic and galvanostatic electrodeposition conditions in melts is considered.

Growth of single silver crystals during electrodeposition from a melt in the presence of an excess background electrolyte

The regularities of the initial stages of growth of silver nano- and microcrystals during electrodeposition from the AgNO3-KNO3-NaNO3 melt with an excess background electrolyte are studied. A model for the electrocrystallization process is proposed. Experimental and theoretical time dependences of the overpotential (supersaturation) and the crystal size are obtained. The applicability of this model is discussed. The main electrodeposition parameters are found to be the specific capacity of a double electrical layer, the equilibrium concentration of single adatoms at the electrode, and the diffusion coefficient of depositing ions in the melt.

Theory of cyclic voltammetry for electrochemical nucleation and growth

The theory of cyclic voltammetry for processes of 3D nucleation, diffusion-controlled growth, and dissolution is proposed. The cases of single metal cluster formation and multiple nucleation are studied. The main features of cyclic voltammograms are analyzed: current increase on forward scan during nucleation, nucleation loop, maximum cathode current on reverse scan, and anodic peak of metal stripping.

Analysis of the geometrical–probabilistic models of electrocrystallization

The formation of a three-dimensional electrode deposit under potentiostatic conditions, including the stages of nucleation, growth, and overlap of growing new-phase clusters and their diffusion zones, is considered. The models of electrochemical phase formation for kinetics- and diffusion-controlled growth are analyzed, and the correctness of the approximations used in these models is estimated. The possibility of application of these models to an analysis of the electrodeposition of silicon from molten salts is discussed.