Growth patterns in electrodeposition (original) (raw)
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Dynamical growth behavior of copper clusters during electrodeposition
Applied Physics Letters, 2010
Ultrahigh resolution full-field transmission x-ray microscopy enabled us to observe detailed phenomena during the potentiostatic copper electrodeposition on polycrystalline gold. We detected two coexisting cluster populations with different sizes. Their growth behaviors are different, with a shape transitions only occurring for large clusters. These differences influence the micromorphology and general properties of the overlayer.
Heliyon, 2018
Fractal like morphology is a very interesting feature during electrodeposition of metals and shows pattern transition with changes in deposition conditions. In this article, we have explained the thermal effects in the two dimensional DLA morphology on the basis of thermal free energy and another free energy barrier resulting from the electric field. The results obtained from free energy hypothesis are consistent with experiments showing the transition voltage for electrodeposition of copper ions to be around 6 V.
2000
We present a complete study of the Multiparticle Biased Diffusion-Limited Aggregation (MBDLA) model supplemented with surface difussion (SD), focusing on the relevance and effects of the latter transport mechanism. By comparing different algorithms, we show that MBDLA+SD is a very good qualitative model for electrodeposition in practically all the range of current intensities provided one introduces SD in the model in the proper fashion: We have found that the correct procedure involves simultaneous bulk diffusion and SD, introducing a time scale arising from the ratio of the rates of both processes. We discuss in detail the different morphologies obtained and compare them to the available experimental data with very satisfactory results. We also characterize the aggregates thus obtained by means of the dynamic scaling exponents of the interface height, allowing us to distinguish several regimes in the mentioned interface growth. Our asymptotic scaling exponents are again in good agreement with recent experiments. We conclude by discussing a global picture of the influence and consequences of SD in electrodeposition.
Ag/Cu (0 0 1) electrodeposition: beyond the classical nucleation theory
Journal of Electroanalytical Chemistry, 2004
Ag/Cu (0 0 1) electrodeposition is studied in the framework of an atomistic kinetic model handled by Monte Carlo simulations. When the kinetics are controlled by a nucleation and growth process, the Kolmogorov-Johnson-Mehl-Avrami (KJMA) formalism is able to reproduce it. The classical nucleation theory allows one to relate the physical quantities involved in the KJMA equation to the microscopic parameters of the kinetic model. However, to obtain a quantitative agreement with Monte Carlo simulations, the morphology of the clusters, in particular the concentration of kinks, and their degeneracy must be taken into account. This improves the calculation of the edge free energy and the description of the frequencies of attachment and detachment of monomers. This leads to a good agreement with MC simulations in a large range of temperatures for the kinetics of electrodeposition and for the physical quantities that control it, i.e., the steady-state nucleation rate, the asymptotic growth rate and the incubation time.
Experimental aspects of dense morphology in copper electrodeposition
Physical Review A, 1991
We report an extensive study of electrochemical deposition of copper with growth under galvanostatic conditions and parallel geometry. In such conditions a clear understanding of the origin of the ramified deposit and of its growth speed is possible, at least in the case of dense morphology. We confirm that this morphology belongs to a steady-state regime where growth can be modeled as the displacement of a Hat strip of nearly equipotential copper. The growth velocity is exactly the drift velocity of the anions, which is proportional to the current density. We also show that the mass of the deposit does not depend on the speed at which it was grown but only on the concentration of salt in the bulk of the electrolyte. We compute the modifications in concentration profiles and in the electric field due to pH changes during growth.
Electrodeposition dynamics: electrochemical and X-ray scattering studies
Electrochimica Acta, 1998
Studies of the electrodeposition dynamics of underpotential deposition (UPD) processes based on electrochemical and in-situ surface X-ray scattering studies are presented. The studies focus on the UPD of Hg on Au(111) in sulfate media, and Cu UPD on Pt(111) in sulfate and chloride media. In the ®rst case it is shown that Hg UPD on Au(111) in sulfuric acid follows a progressive nucleation mechanism which involves various surface structures. In the case of Cu UPD on Pt , the process appears to follow an instantaneous nucleation mechanism in both sulfate and chloride media. Time-resolved surface X-ray scattering studies of Cu UPD on Pt(111) in the presence of chloride demonstrate that the electrochemical relaxation and the achievement of long range order can take place on signi®cantly dierent time scales. Analysis of time-resolved surface X-ray scattering data allows for the study of the dynamics of island growth. #
Interface dynamics for copper electrodeposition: The role of organic additives in the growth mode
2002
An atomistic model for Cu electrodeposition under nonequilibrium conditions is presented. Cu electrodeposition takes place with a height-dependent deposition rate that accounts for fluctuations in the local Cu 2ϩ ions concentration at the interface, followed by surface diffusion. This model leads to an unstable interface with the development of protrusions and grooves. Subsequently the model is extended to account for the presence of organic additives, which compete with Cu 2ϩ for adsorption at protrusions, leading to a stable interface with scaling exponents consistent with those of the Edwards-Wilkinson equation. The model reproduces the interface evolution experimentally observed for Cu electrodeposition in the absence and in the presence of organic additives.
Geometrical aspect of electrodeposition: The Hecker effect
Physical Review A, 1991
We have studied the growth of electrodeposits from solutions of copper sulfate in thin cells, and focused our attention on the spectacular morphological transitions that occur in almost every experimental condition. We give experimental evidence and numerical and theoretical results showing that these transitions are due to the propagation of charged impurities leaving the dissolving anode at the beginning of the growth and hitting the deposit at later times. The arrival of the impurity front against the growing deposit modifies the growing conditions, thus leaving on the deposit the trace of an almost homothetical "ghost" image of the anode.