Diffusionsgrenzstrom und verwandte Probleme bei Elektrolytschmelzen mit drei ionischen Bestandteilen / Limiting Diffusion Current and Related Problems of Ionic Melts with Three Ion Constituents

1974 ◽  
Vol 29 (12) ◽  
pp. 1935-1936 ◽  
Author(s):  
R. Haase
Keyword(s):  
Interdiffusion Coefficient ◽  
Diffusion Current ◽  
Simultaneous Occurrence ◽  
Ionic Melts ◽  
Electrode Interface ◽  
Electric Flux ◽  
And Diffusion ◽  
Internal Transport ◽  
Limiting Value ◽  
Limiting Diffusion Current

Starting from the general equation for the simultaneous occurrence of electromigration and diffusion in an ionic melt with three ion constituents, we derive the rigorous expression for the electric flux at an electrode interface. This expression contains the ratio of the interdiffusion coefficient of the melt to the internal transport number of the ion constituent that does not cross the interface. In the case of the limiting diffusion current (occurring in the problem of diffusion overvoltage), the electric flux contains the limiting value for infinite dilution of the interdiffusion coefficient.

scholarly journals The Mixed Current Model of Nano-MOSFETs Considering the Effect of Horizontal and Vertical Electric Fields

2019 ◽  
Author(s):  
Heng-Sheng Huang ◽  
Ping-Ray Huang ◽  
Mu-Chun Wang ◽  
Shuang-Yuan Chen ◽  
Shea-Jue Wang ◽  
...  
Keyword(s):  
Electric Fields ◽  
Current Model ◽  
Atomic Layer ◽  
Diffusion Current ◽  
Electrical Performance ◽  
Short Channel ◽  
Drive Current ◽  
Layer Deposition ◽  
And Diffusion ◽  
Better Than

A novel drive current model covering the effects of source/drain voltage (VDS) and gate voltage (VGS) and incorporating drift and diffusion current on the surface channel at the nano-node level, especially beyond 28nm node is presented. The effect of the diffusion current added is more satisfactory to describe the behavior of the drive current in nano-node MOSFETs, fabricated with the atomic-layer-deposition (ALD) technology. This breakthrough in model establishment can expose the long and short channel devices together. Introducing the variables of VDS and VGS, the mixed current model more effectively and meaningfully demonstrates the drive current of MOSFETs under the operation of horizontal, vertical, or mixed electrical field. In comparison between the simulation and experimental consequences, the electrical performance is impressive. The error between both is less than 1%, better than the empirical adjustment to issue a set of drive current models.

scholarly journals Estimation of the exchange current density and comparative analysis of morphology of electrochemically produced lead and zinc deposits

2017 ◽  
Vol 82 (5) ◽  
pp. 539-550
Author(s):  
Nebojsa Nikolic ◽  
Predrag Zivkovic ◽  
Goran Brankovic ◽  
Miomir Pavlovic
Keyword(s):  
Current Density ◽  
Exchange Current ◽  
Exchange Current Density ◽  
Diffusion Current ◽  
Electron Microscopic ◽  
Zinc Electrodeposition ◽  
Lead And Zinc ◽  
Current Densities ◽  
Limiting Diffusion Current ◽  
Zinc Deposits

The processes of lead and zinc electrodeposition from the very dilute electrolytes were compared by the analysis of polarization characteristics and by the scanning electron microscopic (SEM) analysis of the morphology of the deposits obtained in the galvanostatic regime of electrolysis. The exchange current densities for lead and zinc were estimated by comparison of experimentally obtained polarization curves with the simulated ones obtained for the different the exchange current density to the limiting diffusion current density ratios. Using this way for the estimation of the exchange current density, it is shown that the exchange current density for Pb was more than 1300 times higher than the one for Zn. In this way, it is confirmed that the Pb electrodeposition processes are considerably faster than the Zn electrodeposition processes. The difference in the rate of electrochemical processes was confirmed by a comparison of morphologies of lead and zinc deposits obtained at current densities which corresponded to 0.25 and 0.50 values of the limiting diffusion current densities.

Interdiffusion in Short-Wavelength Modulated Materials Studied by Monte-Carlo Simulations

1987 ◽  
Vol 103 ◽  
Author(s):  
M. Atzmon
Keyword(s):  
Monte Carlo ◽  
Monte Carlo Simulations ◽  
Interdiffusion Coefficient ◽  
Short Range ◽  
Short Range Order ◽  
Range Order ◽  
One Dimensional ◽  
Interdiffusion Process ◽  
Limiting Value ◽  
Modulation Wavelength

ABSTRACTInterdiffusion in a two-dimensional compositionally modulated lattice has been studied by Monte-Carlo simulations. In the initial stages, the interdiffusion coefficient has been observed to change with time due to the development of short-range order simultaneously with the interdiffusion process. When the short-range order parameter approached its limiting value, the diffusion coefficient approached a constant value. The dependence of the interdiffusion coefficient on the modulation wavelength does not agree with the prediction of one-dimensional theories. For ordering alloy systems, the effective interdiffusion coefficient is positive, i.e., an initially present modulation decays in time, for all wavelengths.

scholarly journals The ionic equilibrium in the CuSO4-H2SO4-H2O system and the formation of the honeycomb-like structure during copper electrodeposition

2008 ◽  
Vol 73 (7) ◽  
pp. 753-760 ◽  
Author(s):  
Nebojsa Nikolic ◽  
Ljubica Pavlovic ◽  
Goran Brankovic ◽  
Miomir Pavlovic ◽  
Konstantin Popov
Keyword(s):  
Hydrogen Evolution ◽  
Current Density ◽  
Diffusion Current ◽  
Copper Electrodeposition ◽  
Hydrodynamic Conditions ◽  
Ionic Equilibrium ◽  
Electrode Layer ◽  
Limiting Diffusion Current

The ionic equilibrium of the species in the CuSO4-H2SO4-H2O system was employed to systematize the conditions of copper electrodeposition leading to the formation of the honeycomb-like structure. The reason why CuSO4 concentrations higher than 0.15 M are unsuitable for the formation of honeycomb-like structures is shown. The range of H2SO4 concentrations enabling the formation of this type of structure was also determined. The conditions leading to the formation of the honeycomb-like structures are: electrodeposition from solutions with lower concentrations of Cu(II) ions (0.15 M CuSO4 and less) in a concentration range from 0.25 to 1.0 M H2SO4, at a temperature of 18.0?1.0 ?C and at overpotentials outside the plateau of the limiting diffusion current density at which hydrogen evolution is vigorous enough to change the hydrodynamic conditions in the near-electrode layer. .

Effective Diffusion Coefficient

2018 ◽  
Vol 384 ◽  
pp. 130-135
Author(s):  
Jorge A. Gordillo
Keyword(s):  
Interdiffusion Coefficient ◽  
Nanocrystalline Materials ◽  
Effective Diffusion ◽  
Average Frequency ◽  
Solute Diffusion ◽  
Segregation Coefficient ◽  
Two Phase ◽  
Random Walk Theory ◽  
And Diffusion ◽  
Impurities And Diffusion

The diffusion of a B element into an A matrix was studied by the random walk theory. Considering that concentration of B element in the A matrix is very low, the jumps of diffusing atoms are independent of each other. The A matrix is a two-region material with different properties, such as a two-phase material, a single crystal with dislocations, or regions influenced by other solute and a polycrystalline material.It is assumed that material B has a penetration that allows it to cross each region of material A several times. This implies that jumps across the surface between those regions have an average frequency and, as a consequence, there is an interdiffusion coefficient between them. The interdiffusion coefficient between those regions is different than the coefficient of the diffusion in each region.Expressions were obtained that allow to delimit the ranges of validation with greater precision than the corrected Hart-Mortlock equation for solute diffusion. In addition, an original relationship was obtained between the segregation coefficient and parameters specific to the diffusion. New powerful tools were also found that can help to understand diffusion in nanocrystalline materials, diffusion in metals influenced by impurities and diffusion produced by different mechanisms.

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