Variation of the dielectric constant of anodic oxide films on titanium with oxygen evolution

1995 ◽  
Vol 25 (9) ◽  
pp. 881-885 ◽  
Author(s):  
M. A. Abdel Rahim
Keyword(s):  
Dielectric Constant ◽  
Oxygen Evolution ◽  
Oxide Films ◽  
Anodic Oxide ◽  
Anodic Oxide Films

The determination of the thickness, dielectric constant, and other properties of anodic oxide films on tantalum from the interference colours

1958 ◽  
Vol 244 (1236) ◽  
pp. 41-53 ◽  
Keyword(s):  
Dielectric Constant ◽  
Refractive Index ◽  
Oxide Films ◽  
Anodic Oxide ◽  
Effective Dielectric Constant ◽  
Immersion Method ◽  
Anodic Oxide Films ◽  
A Value ◽  
Specular Reflectivity

The thickness of anodic oxide films on chemically polished tantalum was determined from the wavelengths of the minima in the specular reflectivity using a value of the refractive index of 2·20±0·02 at 5900 Ǻ which was measured on detached flakes of the oxide by the immersion method. An auxiliary measure of increments of thickness was required for the analysis of the spectrophotometric measurements. This was provided by the quantity ( Q ∆( 1/ C )) ½ , where Q was the charge which was required to form the increment of thickness, and ∆(1/ C ) was the corresponding increase in the reciprocal capacity. This measure of thickness, like that provided by the colours, is independent of the area. The analysis gives the refractive index between 2800 and 6000 Ǻ, the net phase change in the two reflexions (with certain assumptions), and a value of ϵ/ρ, where ϵ is the effective dielectric constant under the conditions used, and ρ is the density, ρ was determined by weighing specimens in air and water. The value obtained was 7·93 ± 3%, which gives ϵ = 27·6±5%, at 1 kc/s. The effective surface area was then calculated, and was found to be very little different from the apparent area. The field strength during the formation of oxide at 9·55 mA/cm 2 and 25·8° C was found to be 6·61 x 10 6 V/cm and to be constant within experimental error, independent of thickness.

Crystallization in anodic oxide films

1988 ◽  
Vol 28 (1) ◽  
pp. 43-56 ◽  
Author(s):  
J.S.L. Leach ◽  
B.R. Pearson
Keyword(s):  
Oxide Films ◽  
Anodic Oxide ◽  
Anodic Oxide Films
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