An ultrahigh vacuum compatible fluorine atom source for gas–surface reaction studies

AbstractEffects of H irradiation on purifying Cu films and improving their surface roughness as well as size and orientation of Cu grains in the films have been examined using a newly developed plasma CVD reactor equipped with an H atom source, in which Cu(hfac)2 is supplied as the source material. The H irradiation is effective in purifying the Cu films, increasing the grain size, and reducing the surface roughness, while it has no effect on the grain orientation. The decrease in dissociation degree of material gas leads to reduction of the surface reaction probability of Cu- containing radicals, which is important to realize conformal deposition in fine trenches. Using the control of dissociation degree of material gas independent of H irradiation, we have demonstrated conformal deposition of smooth Cu films in the trench using the developed plasma CVD reactor.

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SURFRESIDE2: An ultrahigh vacuum system for the investigation of surface reaction routes of interstellar interest

Review of Scientific Instruments ◽

10.1063/1.4816135 ◽

2013 ◽

Vol 84 (7) ◽

pp. 073112 ◽

Cited By ~ 32

Author(s):

S. Ioppolo ◽

G. Fedoseev ◽

T. Lamberts ◽

C. Romanzin ◽

H. Linnartz

Keyword(s):

Surface Reaction ◽

Ultrahigh Vacuum ◽

Vacuum System ◽

Reaction Routes

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Correlations in the calculation of electron scattering on fluorine atom

Scientific Herald of Uzhhorod University Series Physics ◽

10.24144/2415-8038.2015.37.128-138 ◽

2015 ◽

Vol 37 (0) ◽

pp. 128-138

Author(s):

Є. А. Нодь ◽

В. Ю. Лазур

Keyword(s):

Electron Scattering ◽

Fluorine Atom

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EVALUATION OF LUBRICANTS AT HIGH AND LOW TEMPERATURES IN ULTRAHIGH VACUUM

10.2514/6.1966-2211 ◽

1966 ◽

Author(s):

L. MCCRARY ◽

T. BRADLEY ◽

J. PARKS

Keyword(s):

Low Temperatures ◽

Ultrahigh Vacuum ◽

High And Low Temperatures

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Modeling the Electrical Double Layer to Understand the Reaction Environment in a CO2 Electrocatalytic System

10.26434/chemrxiv.9206075.v1 ◽

2019 ◽

Author(s):

Divya Bohra ◽

Jehanzeb Chaudhry ◽

Thomas Burdyny ◽

Evgeny Pidko ◽

wilson smith

Keyword(s):

Electric Field ◽

Double Layer ◽

Electrical Double Layer ◽

Surface Reaction ◽

Catalyst Surface ◽

Local Reaction ◽

Reaction Diffusion ◽

Alkali Metal Cations ◽

Applied Potential ◽

Critical Aspect

The environment of a CO2 electroreduction (CO2ER) catalyst is intimately coupled with the surface reaction energetics and is therefore a critical aspect of the overall system performance. The immediate reaction environment of the electrocatalyst constitutes the electrical double layer (EDL) which extends a few nanometers into the electrolyte and screens the surface charge density. In this study, we resolve the species concentrations and potential profiles in the EDL of a CO2ER system by self-consistently solving the migration, diffusion and reaction phenomena using the generalized modified Poisson-Nernst-Planck (GMPNP) equations which include the effect of volume exclusion due to the solvated size of solution species. We demonstrate that the concentration of solvated cations builds at the outer Helmholtz plane (OHP) with increasing applied potential until the steric limit is reached. The formation of the EDL is expected to have important consequences for the transport of the CO2 molecule to the catalyst surface. The electric field in the EDL diminishes the pH in the first 5 nm from the OHP, with an accumulation of protons and a concomitant depletion of hydroxide ions. This is a considerable departure from the results obtained using reaction-diffusion models where migration is ignored. Finally, we use the GMPNP model to compare the nature of the EDL for different alkali metal cations to show the effect of solvated size and polarization of water on the resultant electric field. Our results establish the significance of the EDL and electrostatic forces in defining the local reaction environment of CO2 electrocatalysts.

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Non-Toxic Environment for Ferritic Nitrocarburising Process

Revista de Chimie ◽

10.37358/rc.18.9.6587 ◽

2018 ◽

Vol 69 (9) ◽

pp. 2416-2419

Author(s):

Mihai Branzei ◽

Mihai Ovidiu Cojocaru ◽

Leontin Nicolae Druga ◽

Florica Tudose ◽

Roxana Trusca

Keyword(s):

Surface Reaction ◽

Effective Solution ◽

Reaction Products ◽

Toxic Reaction ◽

Wide Range ◽

Toxic Environment ◽

Thermochemical Processing ◽

Surface Saturation ◽

Gas Molecules ◽

Toxic Components

Experimental research aimed to find a solution for replacing components with high toxicity (or generating such components as a result of reactions occurring in the environment at processing temperatures) from the environments used for ferritic nitrocarburising process (FNCP) with non-hazardous components, but extremely active during the process. In the temperature range in which this type of processing is applied (lower than the eutectoid transformation temperature in the Fe-N phase diagram), the most commonly used media are liquid or gaseous; liquid ones contain toxic components (sodium or potassium cyanates/cyanides), and gaseous ones require complex equipments. Packing is extremely rarely used, but in this case pack-mix contain toxic components (15 � 20 wt.% sodium or potassium ferrocyanide). Urea also called carbamide (CO (NH2)2) is the active component in the pack-mixing proposed to be used for FNCP. Carbamide is used in low temperature cyanidation thermochemical heat treatment (liquid FNC), together with sodium or potassium carbonates, resulting in very toxic reaction products (sodium or potassium cyanates). Compared to cyanidation, in the version proposed in the paper, the carbamide does not react with carbonates because they are not found in the composition of the environment but decomposes in the presence or absence of oxygen (by a disproportionation reaction) with the formation of some gas molecules interesting for the process. It has been concluded that the use of carbamide together with two other components, activated charcoal (having a triple role - dispersing, storage, surface saturation) and respectively ammonium chloride as surface reaction activator, is an effective solution for achieving the desired goals by applying this type of thermochemical processing to a wide range of products made of quality steels up to alloy miscellaneous steels.

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