Structural Transformations of Amorphous Carbon (Glassy Carbon) at High Shock Pressures

2018 ◽  
Vol 126 (6) ◽  
pp. 772-778 ◽  
Author(s):  
A. M. Molodets ◽  
A. A. Golyshev
Keyword(s):  
Amorphous Carbon ◽  
Glassy Carbon ◽  
Structural Transformations ◽  
High Shock

Electron-diffraction studies of amorphous carbon thin films

1993 ◽  
Vol 51 ◽  
pp. 1100-1101
Author(s):  
David A. Muller
Keyword(s):  
Thin Films ◽  
Electron Diffraction ◽  
Amorphous Carbon ◽  
Glassy Carbon ◽  
Spherical Structure ◽  
Local Ordering ◽  
Carbon Arc ◽  
Similar Appearance ◽  
Carbon Thin Films ◽  
Large Spherical

The sp2 rich amorphous carbons have a wide variety of microstructures ranging from flat sheetlike structures such as glassy carbon to highly curved materials having similar local ordering to the fullerenes. These differences are most apparent in the region of the graphite (0002) reflection of the energy filtered diffracted intensity obtained from these materials (Fig. 1). All these materials consist mainly of threefold coordinated atoms. This accounts for their similar appearance above 0.8 Å-1. The fullerene curves (b,c) show a string of peaks at distance scales corresponding to the packing of the large spherical and oblate molecules. The beam damaged C60 (c) shows an evolution to the sp2 amorphous carbons as the spherical structure is destroyed although the (220) reflection in fee fcc at 0.2 Å-1 does not disappear completely. This 0.2 Å-1 peak is present in the 1960 data of Kakinoki et. al. who grew films in a carbon arc under conditions similar to those needed to form fullerene rich soots.

Micro-Texturing onto Amorphous Carbon Materials as a Mold-Die for Micro-Forming

2013 ◽  
Vol 289 ◽  
pp. 23-37 ◽  
Author(s):  
Tatsuhiko Aizawa
Keyword(s):  
Amorphous Carbon ◽  
Glassy Carbon ◽  
Carbon Materials ◽  
Hot Stamping ◽  
High Strength ◽  
Solid Material ◽  
Carbon Substrate ◽  
Micro Forming ◽  
Dlc Coating ◽  
Polymer Sheets

Among various kinds of carbon materials, two types of amorphous carbon were employed as a mold-die material for micro-forming. Diamond like carbon (DLC) has sufficient strength and toughness as a protective coating onto the steel and WC (Co) substrates. Glassy carbon is a solid material which also has high strength even at the elevated temperature under inert gas atmosphere. These two materials are selected to fabricate the micro-textured mold-die as a mother tool to duplicate this micro-textured pattern onto the metallic and polymer sheets via table-top CNC micro-forming systems. High density oxygen-plasma etching and pico-second laser machining were developed to make micro-texturing onto the above two mold-die materials. In the former, micro-groove and micro-grid patterns were formed on the DLC coating; table-top CNC stamping system with CNC-feeder and cropper was used to duplicate these patterns onto the aluminum sheets in dry and at the room temperature. In the latter, micro-wedge patterns were imprinted onto the glassy carbon substrate; table-top CNC mold-stamping system with heating equipment was utilized for duplication of these patterns onto thermoplastic polymer sheets above the glass transition temperature. Formation of micro-textures onto these amorphous carbon materials provides us a new tool to fabricate the micro-patterned parts and devices in mass production via cold and hot stamping processes.

Transparent, superhard amorphous carbon phase from compressing glassy carbon

2014 ◽  
Vol 104 (2) ◽  
pp. 021916 ◽  
Author(s):  
Mingguang Yao ◽  
Junping Xiao ◽  
Xianhong Fan ◽  
Ran Liu ◽  
Bingbing Liu
Keyword(s):  
Amorphous Carbon ◽  
Glassy Carbon ◽  
Carbon Phase

scholarly journals 3.0 To 3.5 Micron Spectrum of V348 Sgr and R CrB

1985 ◽  
Vol 87 ◽  
pp. 203-205
Author(s):  
K. Nandy ◽  
N. Kameswara Rao ◽  
D.H. Morgan
Keyword(s):  
Amorphous Carbon ◽  
Glassy Carbon ◽  
Spectral Region ◽  
Dust Emission ◽  
Circumstellar Dust ◽  
Spectral Features ◽  
High Carbon ◽  
Carbon Particles ◽  
Carbon Abundance ◽  
Extinction Peak

The circumstellar dust in R CrB stars is often thought to be due to graphite, because of the high carbon abundance in the stars. Further, the spectra of these stars in the infrared show feature-less smooth continuum (Forrest 1974, Roche and Aitken 1984) which was also thought to be characteristic of graphite. However, the recent comparison of the ultraviolet spectra obtained at maximum and minimum light of R CrB showed an extinction peak in the region of 2400 to 2500A (Holm, Wu & Doherty 1982, Hecht et al. 1984) which was identified as due to amorphous or glassy carbon particles. According to Duley and Williams (1981,83) amorphous carbon is supposed to show spectral features in the 3.3-3.4 μm region. Further many dust emission features are also supposed to appear in the spectral region 3 to 3.5 μm (Aikten 1981). The previous studies in this spectral region in R CrB (Forrest 1974) and in the hotter star V348 Sgr (Allen et al. 1982) showed smooth continuum. V348 Sgr shows spectroscopically many similarities with other WC 11 stars and was grouped with CPD-56°8032, He 2-113 and M4-18 (Webster and Glass 1974). All these three stars show strong dust emission features at 3.3, 8.6 11.25 μm. With a view to search for weaker dust spectral features we obtained the spectrum of R CrB and V348 Sgr with higher resolution than employed before.

scholarly journals STUDY OF THE STRUCTURE AND STRUCTURAL TRANSFORMATIONS IN GLASSY CARBON USING IR-FOURIER SPECTROSCOPY (FTIR)

2018 ◽  
Vol 84 (4) ◽  
pp. 41-46
Author(s):  
A. M. Bekhterev ◽  
I. V. Ryuskugina ◽  
M. P. Baryshnikov ◽  
J. Yu. Efimova ◽  
A. M. Ryzhov
Keyword(s):  
Glassy Carbon ◽  
Structural Transformations ◽  
Fourier Spectroscopy ◽  
Ir Fourier Spectroscopy
Sign in / Sign up

Export Citation Format

Share Document