The 1280 Cm−1 Absorption Line in Amorphous Hydrogenated Boron Carbide

1998 ◽  
Vol 517 ◽  
Author(s):  
Shu-Han Lin ◽  
Bernard J. Feldman
Keyword(s):  
Boron Carbide ◽  
Infrared Absorption ◽  
Carbon Concentration ◽  
Boron Concentration ◽  
Peak Position ◽  
Intense Line ◽  
Integrated Intensity ◽  
Amorphous Hydrogenated Boron Carbide ◽  
Carbon Concentrations ◽  
Absorption Measurements

AbstractWe report infrared absorption measurements that provide evidence for the presence of boron carbide icosahedra in amorphous hydrogenated boron carbide thin films. The infrared absorption spectra is dominated by an intense line at 1280 cm-1 with a FWHM of ≃320 cm-1. Similar lines have been previously reported in polycrystalline boron carbide, where boron carbide icosahedra make up the unit cell. In both systems, the linewidth narrows and the peak position shifts to higher energy with increasing carbon concentrations. From annealing studies of amorphous hydrogenated boron carbide, hydrogen plays a very small role in the 1280 cm-1 line. Finally, the integrated intensity of the 1280 cm-1 line is a sublinear function of the boron concentration, providing further evidence that the carbon concentration in these icosahedra increases as the carbon concentration of the film increases.

Microhardness, Structure, and Composition Study of Amorphous Hydrogenated Boron Carbide

1995 ◽  
Vol 383 ◽  
Author(s):  
Shu-Han Lin ◽  
Dong Li ◽  
Bernard J. Feldman
Keyword(s):  
Thin Films ◽  
Chemical Composition ◽  
Optical Absorption ◽  
Boron Carbide ◽  
Infrared Absorption ◽  
Rf Plasma ◽  
Plasma Decomposition ◽  
Optical Bandgaps ◽  
Composition Study ◽  
Amorphous Hydrogenated Boron Carbide

ABSTRACTWe have grown amorphous hydrogenated boron carbide thin films by rf plasma decomposition of diborane and methane. The chemical composition, infrared absorption, optical absorption, and microhardness of these thin films were measured. As a function of increasing diborane concentration in the feedstock, we observe increasing boron and hydrogen concentrations, increasing infrared absorption at 1330 cm−1 due to boron icosahedra, increasing optical bandgaps, and an unchanging microhardness in the grown films. The microhardness should have decreased due to the increasing hydrogen concentration; this expected decrease may have been balanced by an increased microhardness due to the boron icosahedra.

Microhardness Study Of Cathode-Mounted Amorphous Hydrogenated Boron Carbide

1996 ◽  
Vol 436 ◽  
Author(s):  
Shu-Han Lin ◽  
Dong Li ◽  
Bernard J. Feldman
Keyword(s):  
Thin Films ◽  
Chemical Composition ◽  
Boron Carbide ◽  
Infrared Absorption ◽  
Band Gaps ◽  
Rf Plasma ◽  
Microhardness Study ◽  
Optical Band Gaps ◽  
Plasma Decomposition ◽  
Amorphous Hydrogenated Boron Carbide

AbstractWe have grown cathode-mounted amorphous hydrogenated boron carbide thin films by rf plasma decomposition of diborane and methane. The chemical composition, infrared absorption, optical absorption, microhardness and adhesion of these thin films were measured. As a function of increasing diborane concentration in the feedstock, we observe increasing boron and decreasing hydrogen concentrations, increasing infrared absorption at 1300 cm-1 due to boron icosahedra, increasing optical band gaps, dramatically increased microhardness, and increased adhesion to the underlying substrates of these thin films. These results provide evidence that the presence of boron icosahedra increases microhardness, adhesion, and optical band gaps.

scholarly journals Traffic Density-Related Black Carbon Distribution: Impact of Wind in a Basin Town

2021 ◽  
Vol 18 (12) ◽  
pp. 6490
Author(s):  
Borut Jereb ◽  
Brigita Gajšek ◽  
Gregor Šipek ◽  
Špela Kovše ◽  
Matevz Obrecht
Keyword(s):  
Black Carbon ◽  
Carbon Concentration ◽  
Ground Level ◽  
Traffic Density ◽  
Carbon Distribution ◽  
Wind Speeds ◽  
Black Carbon Concentration ◽  
Low Wind Speeds ◽  
Temperature Inversions ◽  
Carbon Concentrations

Black carbon is one of the riskiest particle matter pollutants that is harmful to human health. Although it has been increasingly investigated, factors that depend on black carbon distribution and concentration are still insufficiently researched. Variables, such as traffic density, wind speeds, and ground levels can lead to substantial variations of black carbon concentrations and potential exposure, which is even riskier for people living in less-airy sites. Therefore, this paper “fills the gaps” by studying black carbon distribution variations, concentrations, and oscillations, with special emphasis on traffic density and road segments, at multiple locations, in a small city located in a basin, with frequent temperature inversions and infrequent low wind speeds. As wind speed has a significant impact on black carbon concentration trends, it is critical to present how low wind speeds influence black carbon dispersion in a basin city, and how black carbon is dependent on traffic density. Our results revealed that when the wind reached speeds of 1 ms−1, black carbon concentrations actually increased. In lengthy wind periods, when wind speeds reached 2 or 3 ms−1, black carbon concentrations decreased during rush hour and in the time of severe winter biomass burning. By observing the results, it could be concluded that black carbon persists longer in higher altitudes than near ground level. Black carbon concentration oscillations were also seen as more pronounced on main roads with higher traffic density. The more the traffic decreases and becomes steady, the more black carbon concentrations oscillate.

High-pressure far-infrared absorption measurements on La1−xCaxMnO3−δ by means of synchrotron radiation

2006 ◽  
Vol 49 (1-2) ◽  
pp. 92-95
Author(s):  
A. Sacchetti ◽  
M. Cestelli Guidi ◽  
E. Arcangeletti ◽  
P. Postorino ◽  
A. Nucara ◽  
...  
Keyword(s):  
High Pressure ◽  
Synchrotron Radiation ◽  
Infrared Absorption ◽  
Far Infrared ◽  
Absorption Measurements

13CNMR spectroscopy of amorphous hydrogenated carbon and amorphous hydrogenated boron carbide

1999 ◽  
Vol 59 (15) ◽  
pp. 9745-9747 ◽  
Author(s):  
Janet Braddock-Wilking ◽  
Shu-Han Lin ◽  
Bernard J. Feldman
Keyword(s):  
Boron Carbide ◽  
Amorphous Hydrogenated Boron Carbide ◽  
Amorphous Hydrogenated Carbon

Influence of Carbon Concentration as Coating on Electrical Conductivity of LiFeSi0.03P0.97O4/C

2021 ◽  
Vol 1028 ◽  
pp. 185-190
Author(s):  
Hafizhah Ellora Della ◽  
Mochamad Zainuri ◽  
Pelangi Az Zahra ◽  
Puri Olyvia Swastika ◽  
Triwikantoro
Keyword(s):  
Electrical Conductivity ◽  
Carbon Concentration ◽  
Research Study ◽  
Raw Materials ◽  
Carbon Sources ◽  
Xrd Analysis ◽  
Si Doping ◽  
Diffraction Peaks ◽  
Materials Used ◽  
Carbon Concentrations

This research study about the influence of carbon concenttration as coating on electrical conductivity of LiFeSi0.03P0.97O4/C. Synthesis of LiFeSi0.03P0.97O4/C was carried out different carbon concentrations of 7, 9, and 11 wt%. The raw materials used are Fe2O3, Li2CO3, (NH4)2HPO4, SiO2 as ion Si doping, and glucose as carbon sources. The XRD analysis results showed that all the diffraction peaks in samples were the olivine LiFePO4 phase. From the EIS result, Samples with the addition carbon concentration of 9 wt% produce the highest electrical conductivity values of 4.18 x 10-7 S/cm.

scholarly journals Near Infrared Absorption of Ethylene between 8200 cm-1 and 9500 cm-1 to High Pressures and Temperatures

1976 ◽  
Vol 31 (12) ◽  
pp. 1690-1695 ◽  
Author(s):  
F. W. Nees ◽  
M. Buback
Keyword(s):  
Infrared Absorption ◽  
High Frequency ◽  
Near Infrared ◽  
High Pressures ◽  
High Temperature Phase ◽  
Temperature Phase ◽  
Experimental Conditions ◽  
High Pressure High Temperature ◽  
Wide Range ◽  
Integrated Intensity

AbstractThe near infrared absorption of pure ethylene in the region of the second overtone of the C-H stretching fundamentals (8200 cm-1 to 9500 cm-1) was measured at supercritical temperatures (Tc = 9.5 °C) between 22 °C and 200 °C from 0.7 bar to 3000 bar. The density and temperature dependence of bandshape, maximum frequency and absorption intensity are reported and discussed. The bands observed within a wide range of experimental conditions are assigned to combination and overtone modes. The molar integrated intensity B̅λ determined between the wavelength of maximum absorption and the high frequency absorption boundary was observed to be independent of pressure and temperature. This enables spectroscopic concentration determinations on ethylene in high pressure - high temperature phase equilibria and reactions.

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