Characteristics of Anodic and Corrosion Films on Zirconium

A survey of the polarization behavior (both cathodic and anodic) of sixteen metals in boiling, distilled water is presented. For the current densities used, no simple relation such as the Tafel plot described the dependence of E on I. For many metal‐water systems reliable and reproducible data have been obtained, although in some of these systems the poor reproducibility is not reassuring. Thus, several systems lend themselves to more thorough study.

Section: Exp Acrmentioning

confidence: 89%

The Polarization of Metals in Boiling, Distilled Water

Draley¹,

Boer²,

Youngdahl³

1961

“…It is based on the fact that fission fragment tracks in mica crystals can be revealed by etching. [1]. After an exposure to a thermal neutron flux r the number of fission fragments per unit area (p) which have crossed over into the mica is p= (1/2)RoN~r [1] where aq is the isotopic abundance of U 235, ~ the fission cross section of U ~35, and Ro the effective fission fragment range in germanium.…”

Section: Department Of Metallurgy and Center For Materials Science Anmentioning

confidence: 99%

“…In the course of a study of fission fragment damage in bulk germanium (1), several germanium single crystals doped with uranium were grown successfully. Since such doping experiments have not been reported previously, growth procedure, distribution coefficient, and preliminary results of electrical measurements are presented here.…”

mentioning

confidence: 99%

“…Accordingly, a freshly cleaved mica crystal is placed next to the polished surface of the crystal to be analyzed. After an exposure to a thermal neutron flux r the number of fission fragments per unit area (p) which have crossed over into the mica is p= (1/2)RoN~r [1] where aq is the isotopic abundance of U 235, ~ the fission cross section of U ~35, and Ro the effective fission fragment range in germanium. If Ro is taken as 7 • l0 -4 cm and the fission track density determined with a microscope, the uranium concentration N can be obtained from Eq.…”

mentioning

confidence: 99%

“…If Ro is taken as 7 • l0 -4 cm and the fission track density determined with a microscope, the uranium concentration N can be obtained from Eq. [1]. Such determinations were made on both sides of samples which were later used for electrical measurements.…”

mentioning

confidence: 99%

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Growth and Characterization of Uranium-Doped Germanium Single Crystals

Killias

Dermatis²,

Gatos³

1965

where r is the rate in moles sec -1 cm -2, c is the concentration of KNO3 in moles liter -1, and Po and E are constants.The activation energy, E, is 17.1 kcal mole -1 and Po, which can be regarded as a frequency factor, was found to be 9.2 x 106 cm sec -1. DiscussionCapacitance studies (1) have revealed that freshly prepared anodic zirconium oxide films are permeable to electrolyte solutions, but microscopic evidence indicates that the surface of the oxide is virtually featureless (3). Several suggestions have been made to account for this permeability, the most reasonable being the existence of invisible cracks perpendicular to the film surface (4). Our experimental observations lead to some tentative conclusions about the nature of the oxide film and the permeation process.The permeation rate is fairly reproducible. The small deviations in results can be attributed to variations in the ratio of actual film area to apparent film area. This indicates that a reproducible network of interstices, rather than random gross flaws, serve as paths for permeation. Furthermore, the activation energy for the free diffusion of KC1 in water is 4.4 kcal mole -1 (5) which is nearly four times smaller than the observed activation energy for permeation through the oxide. This also supports the contention that the process is not merely a simple bulk diffusion through large flaws.The relative concentration independence of the constant, P, is difficult to account for if a pore-free barrier layer similar to that found in porous anodic aluminum oxide (6) exists at the oxide-dilute solution interface.) unless CC License in place (see abstract). ecsdl.org/site/terms_use address. Redistribution subject to ECS terms of use (see 128.210.126.199

Hydrated Oxide Films on Aluminum Their Growth and Their Importance in Electrolytic Capacitors

Altenpohl¹,

Post²

1961

The composition and growth of hydrated aluminum oxide films and their dependence on water temperature, reaction time, SiO~ content, and pH are discussed, with special reference to their influence on etched aluminum foils used in electrolytic capacitors. ) unless CC License in place (see abstract). ecsdl.org/site/terms_use address. Redistribution subject to ECS terms of use (see 131.211.208.19 Downloaded on 2015-03-16 to IP