Structural Disorder in Hard Amorphous Carbon Films Implanted with Nitrogen Ions

1995 ◽  
Vol 396 ◽  
Author(s):  
F.L. Freire ◽  
D.F. Franceschini ◽  
C.A. Achete ◽  
R.S. Brusa ◽  
G. Mariotto ◽  
...  
Keyword(s):  
Carbon Film ◽  
Positron Annihilation Spectroscopy ◽  
Structural Disorder ◽  
Carbon Films ◽  
Structural Modifications ◽  
Self Bias ◽  
S Parameter ◽  
Nitrogen Ions ◽  
Amorphous Hydrogenated Carbon

AbstractHard amorphous hydrogenated carbon films deposited by self-bias glow discharge were implanted at room temperature with 70 keV-nitrogen ions at fluences between 2.0 and 9.0×1016 N/cm2. The implanted samples were analyzed by Raman spectroscopy, SIMS and positron annihilation spectroscopy (Doppler broadening technique with the determination of the parameter S. For samples implanted with 2.0x1016 N/cm2 the S parameter follows the vacancies depth profile predicted by Monte Carlo simulation. For higher fluences we observed a reduction in the measured value of S. This result is discussed in terms of both hydrogen loss and structural modifications(increase of disorder at local scale and of the number of graphitic domains) induced in the carbon film by ion implantation.

Fluorine Incorporation Into Hard Amorphous Hydrogenated Carbon Films Deposited by PECVD

1999 ◽  
Vol 593 ◽  
Author(s):  
F. L. Freire ◽  
L. G. Jacobsohn ◽  
D. F. Franceschini
Keyword(s):  
Ion Beam ◽  
Chemical Vapor ◽  
Carbon Films ◽  
Film Deposition ◽  
Density Reduction ◽  
Self Bias ◽  
Amorphous Network ◽  
Vapor Deposition Technique ◽  
Ir Transmission ◽  
Amorphous Hydrogenated Carbon

ABSTRACTThe incorporation of fluorine into amorphous hydrogenated carbon films deposited by the plasma enhanced chemical vapor deposition technique (PECVD) was investigated. Different mixtures of CH4 and CF4 were employed as the plasma atmosphere, with the partial pressure of CF4 ranging from 0 to 100 %. For all depositions, the self-bias was kept at –350 V. In the case of atmospheres richer than ∼80 % of CF4, no film deposition but substrate erosion was observed. The composition of the films was determined by Ion Beam Analysis (IBA), revealing that fluorine is incorporated into the amorphous network by replacing hydrogen. Infrared (IR) transmission measurements confirmed these results. It was also found that the incorporation of fluorine has the effect of reducing both the internal stress and hardness due to atomic density reduction.

Deposition and Etching of Amorphous Carbon Films Prepared by ECR-Plasma-Enhanced Benzene Chemical Vapor Deposition

1998 ◽  
Vol 555 ◽  
Author(s):  
Xiao-Hua Chen ◽  
Laren M. Tolbert ◽  
Z. Y. Ning ◽  
Dennis W. Hess
Keyword(s):  
Chemical Vapor Deposition ◽  
Vapor Deposition ◽  
Electron Cyclotron Resonance ◽  
Carbon Film ◽  
Chemical Vapor ◽  
Carbon Films ◽  
Benzene Vapor ◽  
Plasma Etch ◽  
Ecr Plasma ◽  
Amorphous Hydrogenated Carbon

AbstractAmorphous hydrogenated carbon thin films have been deposited from benzene vapor in a microwave electron cyclotron resonance (ECR) plasma enhanced chemical vapor deposition (CVD) system. Plasma enhanced dissociation and reaction of benzene were monitored by mass spectrometry. Deposited films were characterized by Fourier transform infrared spectroscopy and fluorescence spectroscopy. The effect of the deposition rate on the film density and plasma etch resistance was also studied. The etch resistance of deposited carbon film is higher than the conventional resist Novolac.

Photoluminescence of Amorphous Hydrogenated Carbon Films, a-C:H

1989 ◽  
Vol 149 ◽  
Author(s):  
V. A. Vassilyev ◽  
A. S. Volkov ◽  
E. Musabekov ◽  
E. I. Terukov ◽  
V. E. Chelnokov ◽  
...  
Keyword(s):  
Disordered Systems ◽  
Radiative Recombination ◽  
Structural Disorder ◽  
Carbon Films ◽  
Localized States ◽  
Electron Hole ◽  
High Degree ◽  
Anti Stokes ◽  
Amorphous Hydrogenated Carbon ◽  
Kinetics Of

ABSTRACTResults are presented on the photoluminescence of plasma deposited amorphous carbon (a-C:H) films. Emission and exci tation spectra anti-Stokes emission, PL decay and fatigue, T-dependence of PL and photobleaching were mesuared. The data are discussed in terms of radiative recombination of the strongly localized electron-hole pairs.As recently shown, in amorphous hydrogenated carbon films (a-C:H) powerful talls of localized states occur in the mobility gap that are due to a high degree of structural disorder [1] while a radiative recombination in this material is highly efficient [2, 3]. These properties, in our view, make a-C:H suitable for verification of models of recombination kinetics of photoexcited charge carriers in highly disordered systems with the use of photoluminescence (PL).

Benzylamine Tartrate as an Organic Glass Substrate for Carbon Films by Evaporation

1970 ◽  
Vol 28 ◽  
pp. 484-485
Author(s):  
A. C. Faberge
Keyword(s):  
Vapor Pressure ◽  
Viscous Liquid ◽  
Glass Substrate ◽  
Room Temperature ◽  
Carbon Film ◽  
Carbon Films ◽  
Organic Glass ◽  
Spectroscopic Examination ◽  
Polymeric Substrates

Benzylamine tartrate (m.p. 63°C) seems to be a better and more convenient substrate for making carbon films than any of those previously proposed. Using it in the manner described, it is easy consistently to make batches of specimen grids as open as 200 mesh with no broken squares, and without individual handling of the grids. Benzylamine tartrate (hereafter called B.T.) is a viscous liquid when molten, which sets to a glass. Unlike polymeric substrates it does not swell before dissolving; such swelling of the substrate seems to be a principal cause of breakage of carbon film. Mass spectroscopic examination indicates a vapor pressure less than 10−9 Torr at room temperature.

Carbon Film Deposition On Silicon Using Low Energy Ion Beams

1991 ◽  
Vol 223 ◽  
Author(s):  
Qin Fuguang ◽  
Yao Zhenyu ◽  
Ren Zhizhang ◽  
S.-T. Lee ◽  
I. Bello ◽  
...  
Keyword(s):  
Photoelectron Spectroscopy ◽  
Ion Beam ◽  
Carbon Film ◽  
Carbon Films ◽  
Film Deposition ◽  
Ion Energy ◽  
Transmission Electron ◽  
Higher Temperature ◽  
Post Implantation ◽  
Beam Deposition

ABSTRACTDirect ion beam deposition of carbon films on silicon in the ion energy range of 15–500eV and temperature range of 25–800°C has been studied using mass selected C+ ions under ultrahigh vacuum. The films were characterized with X-ray photoelectron spectroscopy, Raman spectroscopy, and transmission electron microscopy and diffraction analysis. Films deposited at room temperature consist mainly of amorphous carbon. Deposition at a higher temperature, or post-implantation annealing leads to formation of microcrystalline graphite. A deposition temperature above 800°C favors the formation of microcrystalline graphite with a preferred orientation in the (0001) direction. No evidence of diamond formation was observed in these films.

scholarly journals Exploring Secondary Metabolite Profiles of Stachybotrys spp. by LC-MS/MS

Toxins ◽  
2019 ◽  
Vol 11 (3) ◽  
pp. 133 ◽  
Author(s):  
Annika Jagels ◽  
Viktoria Lindemann ◽  
Sebastian Ulrich ◽  
Christoph Gottschalk ◽  
Benedikt Cramer ◽  
...  
Keyword(s):  
Secondary Metabolites ◽  
Future Research ◽  
Structural Modifications ◽  
Metabolite Profiles ◽  
The Individual ◽  
First Time ◽  
Analytical Standards ◽  
Respective Species

The genus Stachybotrys produces a broad diversity of secondary metabolites, including macrocyclic trichothecenes, atranones, and phenylspirodrimanes. Although the class of the phenylspirodrimanes is the major one and consists of a multitude of metabolites bearing various structural modifications, few investigations have been carried out. Thus, the presented study deals with the quantitative determination of several secondary metabolites produced by distinct Stachybotrys species for comparison of their metabolite profiles. For that purpose, 15 of the primarily produced secondary metabolites were isolated from fungal cultures and structurally characterized in order to be used as analytical standards for the development of an LC-MS/MS multimethod. The developed method was applied to the analysis of micro-scale extracts from 5 different Stachybotrys strains, which were cultured on different media. In that process, spontaneous dialdehyde/lactone isomerization was observed for some of the isolated secondary metabolites, and novel stachybotrychromenes were quantitatively investigated for the first time. The metabolite profiles of Stachybotrys species are considerably influenced by time of growth and substrate availability, as well as the individual biosynthetic potential of the respective species. Regarding the reported adverse effects associated with Stachybotrys growth in building environments, combinatory effects of the investigated secondary metabolites should be addressed and the role of the phenylspirodrimanes re-evaluated in future research.

Wear Behavior and Structural Characterization of a Nitrogen Implanted Ti6Al4V Alloy at Different Temperatures

1983 ◽  
Vol 27 ◽  
Author(s):  
R. Martinella ◽  
G. Chevallard ◽  
C. Tosello
Keyword(s):  
Wear Resistance ◽  
Structural Characterization ◽  
Wear Behavior ◽  
Hardened Layer ◽  
Structural Modifications ◽  
Theory Comparison ◽  
Different Temperatures ◽  
Nitrogen Ions ◽  
Wear Tests

ABSTRACTMechanically polished Ti6Al4V samples were implanted with 100 key nitrogen ions to a fluence of 5.1017 ions/cm2 at two different bulk tenneratures: 370°C and 470°C. Wear tests were carried out with a reciprocating slidina tribotester. Structural modifications and wear morphologies were studied by TEM and SEM. 370°C implanted sample showed the same wear behavior as unimplanted ones, while 470°C implanted sample showed better wear resistance because of a TiN hardened layer. Correlations- between microstructural modifications, wear behavior and mechanisms are reported: results agree with the delamination theory. Comparison with ion- and gas-nitrided samples are presented.

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