scholarly journals The Structure and Chemical Composition of the Cr and Fe Pyrolytic Coatings on the MWCNTs’ Surface According to NEXAFS and XPS Spectroscopy

Nanomaterials ◽  
2020 ◽  
Vol 10 (2) ◽  
pp. 374 ◽  
Author(s):  
Danil Sivkov ◽  
Olga Petrova ◽  
Alena Mingaleva ◽  
Anatoly Ob’edkov ◽  
Boris Kaverin ◽  
...  
Keyword(s):  
Chemical Composition ◽  
Photoelectron Spectroscopy ◽  
Chemical Vapor ◽  
Diffraction Order ◽  
Charge Compensation ◽  
Organic Chemical ◽  
Total Electron ◽  
X Ray ◽  
Metal Atoms ◽  
Mwcnts Surface

The paper is devoted to the structure and properties of the composite material based on multi-walled carbon nanotubes (MWCNTs) covered with pyrolytic iron and chromium. Fe/MWCNTs and Cr/MWCNTs nanocomposites have been prepared by the metal organic chemical vapor deposition (MOCVD) growth technique using iron pentacarbonyl and bis(arene)chromium compounds, respectively. Composites structures and morphologies preliminary study were performed using X-ray diffraction, scanning and transmission electron microscopy and Raman scattering. The atomic and chemical composition of the MWCNTs’ surface, Fe-coating and Cr-coating and interface—(MWCNTs surface)/(metal coating) were studied by total electron yield method in the region of near-edge X-ray absorption fine structure (NEXAFS) C1s, Fe2p and Cr2p absorption edges using synchrotron radiation of the Russian-German dipole beamline (RGBL) at BESSY-II and the X-ray photoelectron spectroscopy (XPS) method using the ESCALAB 250 Xi spectrometer and charge compensation system. The absorption cross sections in the NEXAFS C1s edge of the nanocomposites and MWCNTs were measured using the developed approach of suppressing and estimating the contributions of the non-monochromatic background and multiple reflection orders radiation from the diffraction grating. The efficiency of the method was demonstrated by the example of the Cr/MWCNT nanocomposite, since its Cr2p NEXAFS spectra contain additional C1s NEXAFS in the second diffraction order. The study has shown that the MWCNTs’ top layers in composite have no significant destruction; the MWCNTs’ metal coatings are continuous and consist of Fe3O4 and Cr2O3. It is shown that the interface between the MWCNTs and pyrolytic Fe and Cr coatings has a multilayer structure: a layer in which carbon atoms along with epoxy –C–O–C– bonds form bonds with oxygen and metal atoms from the coating layer is formed on the outer surface of the MWCNT, a monolayer of metal carbide above it and an oxide layer on top. The iron oxide and chromium oxide adhesion is provided by single, double and epoxy chemical binding formation between carbon atoms of the MWCNT top layer and the oxygen atoms of the coating, as well as the formation of bonds with metal atoms.

scholarly journals Characterization and Applications of Nanoparticles Modified in-Flight with Silica or Silica-Organic Coatings

Nanomaterials ◽  
2018 ◽  
Vol 8 (7) ◽  
pp. 530 ◽  
Author(s):  
Patrick Post ◽  
Lisa Wurlitzer ◽  
Wolfgang Maus-Friedrichs ◽  
Alfred Weber
Keyword(s):  
Chemical Composition ◽  
Photoelectron Spectroscopy ◽  
Elevated Temperatures ◽  
Chemical Vapor ◽  
Organic Coatings ◽  
Coated Particles ◽  
X Ray ◽  
Transmission Electron ◽  
Coating Composition ◽  
Modification Of The Surface

Nanoparticles are coated in-flight with a plasma-enhanced chemical vapor deposition (PECVD) process at ambient or elevated temperatures (up to 300 °C). Two silicon precursors, tetraethyl orthosilicate (TEOS) and hexamethyldisiloxane (HMDSO), are used to produce inorganic silica or silica-organic shells on Pt, Au and TiO2 particles. The morphology of the coated particles is examined with transmission electron microscopy (TEM) and the chemical composition is studied with Fourier-transform infrared spectroscopy (FTIR), Energy-dispersive X-ray spectroscopy (EDX) and X-ray photoelectron spectroscopy (XPS). It is found that both the precursor and certain core materials have an influence on the coating composition, while other parameters, such as the precursor concentration, aerosol residence time and temperature, influence the morphology, but hardly the chemical composition. The coated particles are used to demonstrate simple applications, such as the modification of the surface wettability of powders and the improvement or hampering of the photocatalytic activity of titania particles.

Preparation of Visible-Light-Responsive Nitrogen-carbon Co-doped Titania by Chemical Vapor Deposition

2010 ◽  
Vol 224 (06) ◽  
pp. 843-856 ◽  
Author(s):  
Yao-Hsuan Tseng ◽  
Chien-Sheng Kuo ◽  
Chia-Hung Huang ◽  
Yuan-Yao Li
Keyword(s):  
Chemical Vapor Deposition ◽  
Visible Light ◽  
Vapor Deposition ◽  
Photoelectron Spectroscopy ◽  
Lattice Structure ◽  
Chemical Vapor ◽  
Organic Chemical ◽  
X Ray ◽  
Doped Titania ◽  
Co Doped

AbstractNitrogen-doped titania (N-doped TiO2) and nitrogen-carbon co-doped titania (N-C-doped TiO2) were prepared in metal-organic chemical vapor deposition (MOCVD) processes under the controlled reaction atmosphere. The N-doped TiO2 and N-C-doped TiO2 with anatase phase were prepared at 600Â oC under N2-O2-NH3 and N2-NH3 atmospheres respectively. The N-C-doped TiO2 exhibited the high photocatalytic activity for the oxidation of NO under visible-light illuminations. The chamber atmosphere in the MOCVD process plays an important role on the surface lattice structure and nitrogen and carbon content of TiO2. The nitrogen and carbonaceous species on the TiO2 surface, evidenced from X-ray diffractometry (XRD), UV-VIS, and Raman spectroscopy, and X-ray photoelectron spectroscopy (XPS), were inferred as important factors for narrowing band gap of titania and enhancement of its visible-light-responsive activity.

Microstructural Changes in Co Films Depending on MOCVD Conditions

2015 ◽  
Vol 1085 ◽  
pp. 12-16
Author(s):  
Rustam Hairullin ◽  
Svetlana Dorovskikh
Keyword(s):  
Chemical Composition ◽  
Surface Morphology ◽  
Structural Parameters ◽  
Chemical Vapor ◽  
Coherent Scattering ◽  
Coherent Scattering Region ◽  
Organic Chemical ◽  
X Ray ◽  
Metal Organic ◽  
Phase And Chemical Composition

In this work the effect of substrate and vaporization temperatures on the structural parameters (sizes of coherent scattering region, values of strain), phase and chemical composition, surface morphology of Co films is revealed. Co films were deposited on Si (100) substrates by Metal-organic chemical vapor deposition using the diiminate complex Co (N’acN’ac)2 as a precursor. The sizes of coherent scattering region, values of strain and phase composition of Co films were determined by the X-ray diffraction analysis. The chemical composition was identified by the Energy-dispersive X-ray spectroscopy. The surface morphology of Co films was investigated by scanning electron microscope. It is found that the variation of deposition conditions allows us widely to change structural parameters and chemical composition of Co films.

X-Ray Photoemission Study of Silicon Nitride-GaAs Interfaces in Relation with GaAs Mesfet Passivation

1987 ◽  
Vol 98 ◽  
Author(s):  
Patrick Alnot ◽  
J. Olivier ◽  
F. Wyczisk ◽  
J. F. Peray ◽  
R. Joubart
Keyword(s):  
Chemical Composition ◽  
Photoelectron Spectroscopy ◽  
Excitation Frequency ◽  
Chemical Vapor ◽  
Gaas Surface ◽  
Surface Pretreatment ◽  
X Ray ◽  
Chemical Vapor Deposited ◽  
Plasma Excitation ◽  
Photoemission Study

ABSTRACTWe have studied the influence of different GaAs surface treatments on the chemical composition and electrical behavior of the Si 3 N4 -GaAs interface, where Si 3 N4 was plasma enhanced chemical vapor deposited (PECVD) onto the treated GaAs(100) substrate. The chemistry of the resulting interface has been studied by X-ray photoelectron spectroscopy (XPS). It has been demonstrated that the chemical composition of the Si 3 N4-GaAs interface is drastically dependent on GaAs surface pretreatment and r.f. plasma excitation frequency. Output-input powers characteristics have been measured on chemically treated planar MESFET after Si3N4. passivation.

scholarly journals Effect of Cellulose Nanocrystals on the Coating of Chitosan Nanocomposite Film Using Plasma-Mediated Deposition of Amorphous Hydrogenated Carbon (a–C:H) Layers

2020 ◽  
Vol 6 (3) ◽  
pp. 51 ◽  
Author(s):  
Torben Schlebrowski ◽  
Zineb Kassab ◽  
Mounir El Achaby ◽  
Stefan Wehner ◽  
Christian B. Fischer
Keyword(s):  
Chemical Composition ◽  
Cellulose Nanocrystals ◽  
Photoelectron Spectroscopy ◽  
Nanocomposite Film ◽  
Chemical Vapor ◽  
Good Alternative ◽  
Ex Situ ◽  
X Ray ◽  
Wide Range ◽  
Amorphous Hydrogenated Carbon

The substitution of petroleum-based polymers with naturally derived biopolymers may be a good alternative for the conservation of natural fossil resources and the alleviation of pollution and waste disposal problems. However, in order to be used in a wide range of applications, some biopolymers’ properties should be enhanced. In this study, biocompatible, non-toxic, and biodegradable chitosan (CS) film and CS reinforced with 10 wt% of cellulose nanocrystals (CN–CS) were coated with amorphous hydrogenated carbon layers (a–C:H) of different thickness. To investigate the effect of the nano-reinforcement on the a–C:H layer applied, mild radio frequency plasma enhanced chemical vapor deposition (RF-PECVD) was used to coat the CS and its CN–CS bio-nanocomposite film. Both the surface characteristics and the chemical composition were analyzed. The surface morphology and wettability were examined by ex-situ atomic force microscopy (AFM) and contact angle measurements (CA), respectively. Hereby, the relationship between sp2/sp3 ratios on a macroscopic scale was also evaluated. For the investigation of the chemical composition, the surface sensitive synchrotron X-ray radiation techniques near edge X-ray absorption fine structure (NEXAFS) and X-ray photoelectron spectroscopy (XPS) as well as diffuse reflectance infrared Fourier transform spectroscopy (DRIFT) were used.

Studies on the Heterostructure of Fe Film on Si Substrate

2005 ◽  
Vol 475-479 ◽  
pp. 3753-3756
Author(s):  
Y.F. Ge ◽  
Rong Zhang ◽  
Xiang Qian Xiu ◽  
Zi Li Xie ◽  
Shu Lin Gu ◽  
...  
Keyword(s):  
Single Crystal ◽  
Photoelectron Spectroscopy ◽  
Chemical Vapor ◽  
Iron Film ◽  
Organic Chemical ◽  
X Ray ◽  
Si Substrates ◽  
Long Time ◽  
The Difference ◽  
Oxidation In Air

Fe films have been grown on different oriented Si substrates by metal organic chemical vapor deposition (MOCVD), and then samples are put in the air without any protection for nearly fifteen years. In this paper, using methods such as X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS) and vibrating sample magnetometer (VSM), we make a detailed research on the samples. We identify the composition and structure of the epitaxial films on different oriented substrates and compare the difference both in composition and magnetic properties. Different orientation of the substrates results in different epitaxial film with different characteristic. We also confirm the existence of single crystal iron in the heteroepitaxial film grown on Si (001), and discuss the possible reason why the single crystal iron film still exists without complete oxidation in air for such a long time.

Adjust the Content of Nickel in NiZnO Films by Vacuum Anneal

2012 ◽  
Vol 562-564 ◽  
pp. 11-14 ◽  
Author(s):  
Xin Dong ◽  
Jin Wang ◽  
Hui Wang ◽  
Zhi Feng Shi ◽  
Bao Lin Zhang
Keyword(s):  
Photoelectron Spectroscopy ◽  
Chemical Vapor ◽  
Lattice Parameter ◽  
Organic Chemical ◽  
X Ray Diffraction ◽  
X Ray ◽  
Different Temperatures ◽  
Metal Organic ◽  
Dramatic Shift ◽  
Anneal Temperature

NiZnO films were grown on sapphire substrates by metal-organic chemical vapor deposition (MOCVD). Then the films were annealed in vacuum at different temperatures for 1h. The UV emission peak was blue shifted in the photoluminescence (PL) spectra and a dramatic shift of (002) diffraction peak to higher angle was observed in X-ray diffraction (XRD) pattern with the increasing anneal temperature. It showed the band gap and the lattice parameter of NiZnO had been affected by anneal in vacuum. From the X-ray photoelectron spectroscopy (XPS) of the NiZnO film, we can find that the anneal temperature had an important effect on the content of each element in NiZnO quantificationally. In addition, the value of x in NiZnO varied slightly with the anneal temperature increasing. The above phenomena indicated that anneal in vacuum could slightly adjust the percentage of Ni indirectly in NiZnO film and offer a good idea in NiZnO devices facture.

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