Some Observations of Copper Deposits on Single Crystals of Copper

415

311

Measurements have been made of the growth rate of zinc dendrites in alkaline zincate solutions as a function of overpotential (n), concentration (c), and temperature (T). The tip radii have been measured by electron microscopy. At constant potential, an initiation time of between 5 and 100 rain is observed, depending on ~, c, and T. The dendrite grows linearly with time, at a rate depending on n, c, and T. The total current to base and dendrite was independent of time until a time T~, where ~ > Ta (the time for initiation obtained from the growth rate vs. time relation). Thereafter, i ~ t 2. A critical

Section: Total Current-time Phenomenon--the Increase Inmentioning

confidence: 99%

mentioning

confidence: 99%

The Mechanism of the Dendritic Electrocrystallization of Zinc

Diggle

Despić

Bockris³

1969

415

311

“…p << n and thus n ~ n ~ ~ po) Eq. [1] may be written for the interstitial case as J ------Did (p + n)/dx + epoE/(kT) -k P~ ~1/(kT) ] [7] Differential forms of Eq. [6] and [7] may be combined with Poisson's equation (i.e., dE/dx = --ep/eeo) to give…”

Section: Statement Of the Problemmentioning

confidence: 99%

“…Denoting the two ions by subscripts 1 and 2, two parallel flux equations may be written following Eq. [7]. We assume that the ions exhibit separate partial molar volumes, interstitial diffusion coefficients and energies of defect formation and that the conditions for local equilibrium discussed previously hold independently for each ion.…”

Section: Statement Of the Problemmentioning

confidence: 99%

Stress Induced Binary Diffusion in a Solid

Charles

1969

Operational methods are used to describe the migration transients of two ions which respond to concentration gradients and ion space charge when a nonuniform stress is applied to a solid. The results indicate two characteristic time constants for the approach to equilibrium. The shorter time constant is related to the establishment of space charge and thus to electrical properties. The long time constant is related to an ion interchange process which depends on the sample geometry.The application of nonuniform mechanical pressure case where more than one ion type responds to applied to a bounded solid containing diffusible ions may restress the electric field from displaced ions is common sult in ion transport and accumulation similar to that to all diffusing species. The effects of concentration obtained by the application of an electric field. For the and stress gradients, however, are specific to the type Vol. 116,No. 11

“…Epitaxial growth of copper single crystals by electrodeposition is very well documented, particularly from sulfate solutions (1)(2)(3)(4)(5)(6)(7)(8). Not so well known, however, is the degree of perfection which can be attained by electrodeposition, as well as the characteristics of the defect structure.…”

mentioning

confidence: 99%

Low Defect Density Electrodeposits on Copper Single Crystals

Bertocci

1971

The electrodeposition of layers of copper over I00 ~m thick on copper single crystals has been carried out on highly perfect copper single crystal substrates, having {111} orientation. Conditions for the achievement of low defect density deposits have been investigated. The defects present in the deposit have been studied by Borrmann topography and other x-ray techniques as well as optical microscopy and dislocation etching. In the most perfect deposits produced, no mosaic structure has been found, and the concentration of defects visible by Borrmann topography did not increase substantially the absorption of the x-ray beam. Small loops or point defect clusters in concentrations of the order of 106/cm 2 have been detected by etching. The orientation of the substrate has been found to affect the perfection of the deposits. It is concluded that random nucleation is likely to be the mechanism for step generation where the orientation is very close to {111}.