Determination of Barrier Layer Thickness of Anodic Oxide Coatings

1954 ◽  
Vol 101 (9) ◽  
pp. 481 ◽  
Author(s):  
M. S. Hunter ◽  
P. Fowle
Keyword(s):  
Layer Thickness ◽  
Barrier Layer ◽  
Anodic Oxide ◽  
Oxide Coatings ◽  
Barrier Layer Thickness

Diagnosis of the Mechanism of Anodic Oxide Film Growth on Platinum in KOH

2016 ◽  
Vol 230 (1) ◽  
Author(s):  
Feixiong Mao ◽  
Pin Lu ◽  
Digby D. Macdonald
Keyword(s):  
Oxide Film ◽  
Electric Field ◽  
Layer Thickness ◽  
Diagnostic Criteria ◽  
Barrier Layer ◽  
Applied Voltage ◽  
Film Growth ◽  
Anodic Oxide ◽  
Anodic Oxide Film ◽  
Barrier Layer Thickness

AbstractDiagnostic criteria for growth of the anodic oxide film on platinum in KOH are reported. In this work, the analytical analysis of oxide film growth demonstrated that the electric field in the passive film formed anodically on platinum in KOH is constant, independent of the applied voltage and barrier layer thickness. This criterion intrinsically distinguishes the Point Defect Model (PDM) from the High Field Model (HFM). Unequivocally, the PDM provides a superior theoretical framework than does the HFM for interpreting oxide film growth on platinum. Importantly, we argue that the diagnostic criteria also apply to metal interstitial conduction, which is the mechanism proposed in the HFM for formation of the PtO oxide film on platinum, but with film growth occurring at the film/solution interface and with a thickness-dependent electric field, rather than being restricted to oxygen vacancy conductors alone, as originally derived for the PDM. Thus, the ability of the diagnostic criteria to differentiate between the HFM and the PDM, in this case, is a direct assessment of the dependence of the electric field strength on the applied voltage and barrier layer thickness, with the experimental results coming down unequivocally on the side of the PDM.

The morphology and mechanism of formation of porous anodic films on aluminium

1970 ◽  
Vol 317 (1531) ◽  
pp. 511-543 ◽  
Keyword(s):  
Steady State ◽  
Layer Thickness ◽  
Current Density ◽  
Barrier Layer ◽  
Anodic Oxide ◽  
Constant Current ◽  
Cell Diameter ◽  
Anodic Films ◽  
Constant Current Density ◽  
Barrier Layer Thickness

The morphology of porous anodic oxide films formed on aluminium in phosphoric acid electrolytes at constant current density or voltage, and under changing electrical or electrolytic conditions, has been studied quantitatively by electron microscopy. Replicas from film sections and from both film interfaces have been prepared, as well as transmission micrographs of thin films, produced under accurately defined conditions. During formation at constant current density, pore initiation occurs by the merging of locally thickening oxide regions, which seem related to the substructure of the substrate, and the consequent concentration of current into the residual thin areas. The pores grow in diameter and change in number until the steady-state morphology is established. The film barrier layer thickness has been measured directly for the first time. The steady-state barrier-layer thickness, cell diameter and pore diameter are all observed to be directly proportional to the formation voltage. It becomes evident that the barrier-layer thickness, decided largely by an equilibrium established between oxide formation in the barrier-layer and field-assisted dissolution (probably thermally enhanced) at the pore bases, determines the cell and pore sizes by a simple geometrical mechanism. Anion incorporation into the film and its hydrogen-bonded structure play secondary roles to these factors in determining the actual film morphology, although not its subsequent properties. A consequence of the mechanism is that, at constant current density, relatively non-aggressive electrolytes give thicker barrier layers, larger cells and larger pores next to the barrier layer than aggressive media, although subsequent pore widening at the outer surface of the film by simple chemical dissolution is more severe in aggressive electrolytes.

Elastic-relaxation-induced barrier layer thickness undulations in InP/GaAs type-II quantum well superlattice structures

2012 ◽  
Vol 27 (10) ◽  
pp. 105031 ◽  
Author(s):  
S D Singh ◽  
Ravi Kumar ◽  
C Mukherjee ◽  
Pushpen Mondal ◽  
A K Srivastava ◽  
...  
Keyword(s):  
Quantum Well ◽  
Layer Thickness ◽  
Barrier Layer ◽  
Type Ii ◽  
Barrier Layer Thickness ◽  
Superlattice Structures

Analysis of Barrier Layer Thickness on Performance of In1–xGaxAs Based Gate Stack Cylindrical Gate Nanowire MOSFET

2018 ◽  
Vol 13 (10) ◽  
pp. 1473-1477 ◽  
Author(s):  
Sanjeev Kumar Sharma ◽  
Jeetendra Singh ◽  
Balwinder Raj ◽  
Mamta Khosla
Keyword(s):  
Layer Thickness ◽  
Barrier Layer ◽  
Significant Variation ◽  
Barrier Thickness ◽  
Gate Stack ◽  
Barrier Layer Thickness ◽  
Nanowire Mosfets ◽  
Silvaco Atlas ◽  
Nanowire Mosfet

In this paper, InGaAs/InP heterostructure based Cylindrical Gate Nanowire MOSFETs (CGNWMOSFET) is designed and its performance has been analyzed using silvaco ATLAS TCAD tool. The influence of the barrier thickness is investigated for perusal performance of an InGaAs/InP heterostructure CGNWMOSFET. The performance compared for various parameters on current, off current, Cut off Frequency (fT), Transconductance (gm), Gate to Source capacitance (Cgs), and Gate to Drain capacitance (Cgd). Results show significant variation in the performance of InGaAs/InP heterostructure CGNWMOSFET by varying the barrier thickness.

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