Characterization of the fluxes of neutral and positively charged clusters (Agn and Ag n + ; n?4) produced by argon ion sputtering of silver

1993 ◽  
Vol 26 (S1) ◽  
pp. 101-103 ◽  
Author(s):  
K. Franzreb ◽  
A. Wucher ◽  
H. Oechsner
Keyword(s):  
Ion Sputtering ◽  
Charged Clusters ◽  
Argon Ion ◽  
Positively Charged

Infrared Characterization of RF Sputter Etching of Polyimide Thin Films

1990 ◽  
Vol 203 ◽  
Author(s):  
S.E. Molis ◽  
D.G. Kim ◽  
S.P. Kowalczyk ◽  
J. Kim
Keyword(s):  
Thin Films ◽  
Infrared Spectroscopy ◽  
Structural Changes ◽  
Surface Damage ◽  
Ion Sputtering ◽  
Absorption Bands ◽  
Damage Layer ◽  
Intensity Changes ◽  
Argon Ion

ABSTRACTWe present infrared spectroscopy as a means of characterizing polyimide structural changes occurring by RF argon ion sputtering. Samples of PMDA-ODA polyimide on chromium coated substrates have been sputter etched from initial thicknesses of 400 Å down to 10 Å. Relative intensity changes in imide vibrational absorption bands have been interpreted in terms of orientational reordering which occurs during the ion sputtering process. The appearance of a new vibration at 1580 cm–1 in the spectra of samples etched below 50 Å is assigned as the Elu mode of graphite corresponding to a surface damage layer which is of a graphitic form.

High-resolution transmission electron microscopic study of highly oxygen doped silicon layer

1989 ◽  
Vol 47 ◽  
pp. 692-693
Author(s):  
H. Takaoka ◽  
M. Tomita ◽  
T. Hayashi
Keyword(s):  
High Resolution ◽  
Oxygen Concentration ◽  
Silicon Layer ◽  
Detailed Structure ◽  
Electron Microscopic ◽  
Cross Sectional ◽  
Transmission Electron ◽  
Doped Silicon ◽  
Argon Ion

High resolution transmission electron microscopy (HRTEM) is the effective technique for characterization of detailed structure of semiconductor materials. Oxygen is one of the important impurities in semiconductors. Detailed structure of highly oxygen doped silicon has not clearly investigated yet. This report describes detailed structure of highly oxygen doped silicon observed by HRTEM. Both samples prepared by Molecular beam epitaxy (MBE) and ion implantation were observed to investigate effects of oxygen concentration and doping methods to the crystal structure.The observed oxygen doped samples were prepared by MBE method in oxygen environment on (111) substrates. Oxygen concentration was about 1021 atoms/cm3. Another sample was silicon of (100) orientation implanted with oxygen ions at an energy of 180 keV. Oxygen concentration of this sample was about 1020 atoms/cm3 Cross-sectional specimens of (011) orientation were prepared by argon ion thinning and were observed by TEM at an accelerating voltage of 400 kV.

scholarly journals Amine substitution into sulfuric acid – ammonia clusters

2012 ◽  
Vol 12 (8) ◽  
pp. 3591-3599 ◽  
Author(s):  
O. Kupiainen ◽  
I. K. Ortega ◽  
T. Kurtén ◽  
H. Vehkamäki
Keyword(s):  
Sulfuric Acid ◽  
Base Substitution ◽  
Free Energies ◽  
Dynamics Model ◽  
Base Exchange ◽  
Charged Cluster ◽  
Charged Clusters ◽  
Evaporation Dynamics ◽  
Ammonia Clusters ◽  
Positively Charged

Abstract. The substitution of ammonia by dimethylamine in sulfuric acid – ammonia – dimethylamine clusters was studied using a collision and evaporation dynamics model. Quantum chemical formation free energies were computed using B3LYP/CBSB7 for geometries and frequencies and RI-CC2/aug-cc-pV(T+d)Z for electronic energies. We first demonstrate the good performance of our method by a comparison with an experimental study investigating base substitution in positively charged clusters, and then continue by simulating base exchange in neutral clusters, which cannot be measured directly. Collisions of a dimethylamine molecule with an ammonia containing positively charged cluster result in the instantaneous evaporation of an ammonia molecule, while the dimethylamine molecule remains in the cluster. According to our simulations, a similar base exchange can take place in neutral clusters, although the overall process is more complicated. Neutral sulfuric acid – ammonia clusters are significantly less stable than their positively charged counterparts, resulting in a competition between cluster evaporation and base exchange.

scholarly journals Characterization of nitrogen species incorporated into graphite using low energy nitrogen ion sputtering

2016 ◽  
Vol 18 (1) ◽  
pp. 458-465 ◽  
Author(s):  
Hisao Kiuchi ◽  
Takahiro Kondo ◽  
Masataka Sakurai ◽  
Donghui Guo ◽  
Junji Nakamura ◽  
...  
Keyword(s):  
Low Energy ◽  
Nitrogen Species ◽  
Ion Sputtering ◽  
Zigzag Edge ◽  
Nitrogen Doped ◽  
Doping Mechanism ◽  
Nitrogen Ions ◽  
Nitrogen Ion

The well-controlled nitrogen doped graphite with graphitic nitrogen located in the zigzag edge and/or vacancy sites can be realized using the low energy nitrogen sputtering. The doping mechanism of nitrogen ions is also discussed.

The use of an LMIS and argon ion sputtering in studies of thin film strain gauges

Vacuum ◽  
1984 ◽  
Vol 34 (1-2) ◽  
pp. 321-325 ◽  
Author(s):  
AG Taylor ◽  
RE Thurstans ◽  
DP Oxley
Keyword(s):  
Thin Film ◽  
Strain Gauges ◽  
Ion Sputtering ◽  
Argon Ion

The red cell band 3 protein: its role in anion transport

1982 ◽  
Vol 299 (1097) ◽  
pp. 497-507 ◽  
Keyword(s):  
Binding Sites ◽  
Band 3 ◽  
Anion Transport ◽  
Anion Binding ◽  
Hydrophobic Residues ◽  
Ping Pong ◽  
Hydrophilic Residues ◽  
Aqueous Core ◽  
Positively Charged

Studies of anion transport across the red blood cell membrane fall generally into two categories: (1) those concerned with the operational characterization of the transport system, largely by kinetic analysis and inhibitor studies; and (2) those concerned with the structure of band 3, a transmembrane peptide identified as the transport protein. The kinetics are consistent with a ping-pong model in which positively charged anion-binding sites can alternate between exposure to the inside and outside compartments but can only shift one position to the other when occupied by an anion. The structural studies on band 3 indicate that only 60 % of the peptide is essential for transport. That particular portion is in the form of a dimer consisting of an assembly of membrane-crossing strands (each monomer appears to cross at least five times). The assembly presents its hydrophobic residues toward the interior of the bilayer, but its hydrophilic residues provide an aqueous core. The transport involves a small conformational change in which an anion-binding site (involving positively charged residues) can alternate between positions that are topologically in and topologically out.

N2 positively charged defects in diamond. A quantum mechanical investigation of the structural, electronic, EPR and vibrational properties

2020 ◽  
Vol 8 (15) ◽  
pp. 5239-5247 ◽  
Author(s):  
Giulio Di Palma ◽  
Francesco Silvio Gentile ◽  
Valentina Lacivita ◽  
William C. Mackrodt ◽  
Mauro Causà ◽  
...  
Keyword(s):  
Ab Initio ◽  
Quantum Mechanical ◽  
Vibrational Properties ◽  
Quantum Mechanical Calculations ◽  
Mechanical Investigation ◽  
Crystal Code ◽  
Charged Defects ◽  
Positively Charged ◽  
Vibrational Characterization

Structural, EPR and vibrational characterization of the N2, N+2 and N++2 defects in diamond from ab initio quantum-mechanical calculations with the CRYSTAL code.

scholarly journals Characterization of distinct molecular interactions responsible for IRF3 and IRF7 phosphorylation and subsequent dimerization

2020 ◽  
Vol 48 (20) ◽  
pp. 11421-11433
Author(s):  
Louise Dalskov ◽  
Ryo Narita ◽  
Line L Andersen ◽  
Nanna Jensen ◽  
Sonia Assil ◽  
...  
Keyword(s):  
Immune Response ◽  
Transcription Factors ◽  
Molecular Interactions ◽  
Adaptor Proteins ◽  
Innate Immune ◽  
Charged Surface ◽  
Regulatory Domain ◽  
Phosphorylation Event ◽  
Positively Charged

Abstract IRF3 and IRF7 are critical transcription factors in the innate immune response. Their activation is controlled by phosphorylation events, leading to the formation of homodimers that are transcriptionally active. Phosphorylation occurs when IRF3 is recruited to adaptor proteins via a positively charged surface within the regulatory domain of IRF3. This positively charged surface also plays a crucial role in forming the active homodimer by interacting with the phosphorylated sites stabilizing the homodimer. Here, we describe a distinct molecular interaction that is responsible for adaptor docking and hence phosphorylation as well as a separate interaction responsible for the formation of active homodimer. We then demonstrate that IRF7 can be activated by both MAVS and STING in a manner highly similar to that of IRF3 but with one key difference. Regulation of IRF7 appears more tightly controlled; while a single phosphorylation event is sufficient to activate IRF3, at least two phosphorylation events are required for IRF7 activation.

scholarly journals Preparation and Characterization of Self-Dispersing Phthalocyanine Blue 15:4 Pigment for Dyeing of Wool Textiles

Coatings ◽  
2020 ◽  
Vol 10 (8) ◽  
pp. 741
Author(s):  
Lun Nie ◽  
Guangtao Chang ◽  
Ruoxin Li
Keyword(s):  
Sulfonic Acid ◽  
Coupling Reaction ◽  
Acid Dyes ◽  
Light Fastness ◽  
Grade 5 ◽  
Weather Resistance ◽  
Sulfonic Acid Groups ◽  
Positively Charged ◽  
Better Than

A self-dispersing pigment was produced by a diazonium coupling reaction; the pigment reacted with aromatic diazonium salts which were generated by the reaction of p-aminobenzene sulfonic acid and sodium nitrite. The surface of the pigment particles was negatively charged due to sulfonic acid groups on the pigment surface. The pigment particle size and zeta potential were, respectively, 134.5 nm and −45.4 mV at neutral pH. The wool surface was positively charged by adjusting the pH; then the anionic self-dispersing pigment dyed the cationic wool. The results show that self-dispersing pigment can adhere well without a binder, and that the K/S value is closely related to pH, dyeing time, and the amount of pigment. The color fastness of the wool was good and the light fastness of the wool was grade 5, which is better than acid dyes. Self-dispersing pigments are potential candidates for dyeing high-weather-resistance textiles.

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