The negative adsorption of chromium atoms on alloy-oxide film boundaries during oxidation in air and anodic passivation of Fe-Cr and Ni-Cr alloys

An anodic oxide film is formed on aluminum in an acidic elecrolyte during anodizing. The structure of the oxide film was observed directly by carbon replica method(l) and ultra-thin sectioning method(2). The oxide film consists of barrier layer and porous layer constructed with fine hexagonal cellular structure. The diameter of micro pores and the thickness of barrier layer depend on the applying voltage and electrolyte. Because the dimension of the pore corresponds to that of colloidal particles, many metals deposit in the pores. When the oxide film is treated as anode in emulsion of polyelectrolyte, the emulsion particles migrate onto the film and deposit on it. We investigated the behavior of the emulsion particles during electrodeposition.Aluminum foils (99.3%) were anodized in either 0.25M oxalic acid solution at 30°C or 3M sulfuric acid solution at 20°C. After washing with distilled water, the oxide films used as anode were coated with emulsion particles by applying voltage of 200V and then they were cured at 190°C for 30 minutes.

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The nature of the oxide film formed on stainless steel immersed in concentrated hydrogen peroxide (H.T.P.)

Journal of Biochemical Toxicology ◽

10.1002/jbt.2570101205 ◽

1960 ◽

Vol 10 (12) ◽

pp. 497-505

Author(s):

J. Diederichsen

Keyword(s):

Hydrogen Peroxide ◽

Stainless Steel ◽

Oxide Film

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Preferential Orientation of Photochromic Gadolinium Oxyhydrides

10.26434/chemrxiv.12377690.v1 ◽

2020 ◽

Author(s):

Elbruz Murat Baba ◽

Jose Montero ◽

Dmitrii Moldarev ◽

Marcos V. Moro ◽

Max Wolff ◽

...

Keyword(s):

Thin Films ◽

Grain Size ◽

Rare Earth ◽

Preferential Orientation ◽

Reactive Magnetron ◽

Flow Ratio ◽

Deposition Pressure ◽

Step Process ◽

Oxidation In Air ◽

Key Parameter

We report preferential orientation control in photochromic gadolinium oxyhydride (GdHO) thin films deposited by a two-step process. Gadolinium hydride (GdH2-x) films were grown by reactive magnetron sputtering, followed by oxidation in air. The preferential orientation, grain size, anion concentrations, and photochromic response of the films are strongly dependent on the deposition pressure. GdHO films show preferential orientation along the [100] direction and exhibit photochromism when synthesized at deposition pressures up to 5.8 Pa and. The photochromic contrast is larger than 20 % when the films are deposited below 2.8 Pa with 0.22 H2/Ar flow ratio. We argue that the degree of preferential orientation defines the oxygen concentration which is known to be a key parameter for photochromism in rare-earth oxyhydride thin films. The experimental observations described above are explained by the oxidation-induced decrease of the grain size as a result of the increase of the deposition pressure of the sputtering gas.

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Surface Microstructure Evolution Upon Silicidation of Ni(Pt) and the Different Responses to Metal Etch

ISTFA 2013: Conference Proceedings from the 39th International Symposium for Testing and Failure Analysis ◽

10.31399/asm.cp.istfa2013p0138 ◽

2013 ◽

Author(s):

Wentao Qin ◽

Dorai Iyer ◽

Jim Morgan ◽

Carroll Casteel ◽

Robert Watkins ◽

...

Keyword(s):

Thin Film ◽

Oxide Film ◽

Microstructure Evolution ◽

Depth Profiling ◽

Surface Microstructure ◽

The Difference ◽

Surface Microstructures ◽

Pt Films

Abstract Ni(5 at.%Pt ) films were silicided at a temperature below 400 °C and at 550 °C. The two silicidation temperatures had produced different responses to the subsequent metal etch. Catastrophic removal of the silicide was seen with the low silicidation temperature, while the desired etch selectivity was achieved with the high silicidation temperature. The surface microstructures developed were characterized with TEM and Auger depth profiling. The data correlate with both silicidation temperatures and ultimately the difference in the response to the metal etch. With the high silicidation temperature, there existed a thin Si-oxide film that was close to the surface and embedded with particles which contain metals. This thin film is expected to contribute significantly to the desired etch selectivity. The formation of this layer is interpreted thermodynamically.

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