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Microscopy studies of deposition of pyrolytic carbon on polished substracts
Pergamon
Carbon Vol. 34, No. II, pp. 1455-1458,
1996 Copyright 0 1996 Elsevier Science Ltd Printed in Great Britain. All rights reserved
OOO8-6223/96$15.00 + 0.00
TANS0 Microscopy Studies Carbon on Polished and A. Oberlin.
No. 171 - ABSTRACTS
of Deposition of Pyrolytic Substracts by J.-F. Despres
adsorptive capacity as a commercial activated carbon could be prepared by prolonged heating at 9OO’C. [TANSO 1996 (No. 17 1) 18-231
Laboratoire Marcel Matbieu, UMR 124, CNRS-DRET-UPP Centre Helioparc, 2 avenue du President Pierre Angot-F64000 PAU.
Microtexture and Crystallinity of Highly Crystallized Graphite Films Prepared from Aromatic Polymide Films II - Effect of Extention of Heat Treatment Time at High Temperature by Yutaka Kaburagi, Akira Yoshida, Hideo Kitahata and Yoshihiro Hishiyama
(no abstract supplied)
[TANSO 1996 (No.171) 2-121 Low Temperature Formation of Graphite Thin Films by Chemical Vapor Deposition by Rie Kikuchi, Masako Yudasaka, Takeo Matsui, Yoshimasa Ohki, Etsuro Ota* and Susumu Yoshimura.
Musashi Institute of Technology,
l-28-1, Tamazutsumi,
Setagaya-
ku,Tokyo 158, Japan.
Yoshimura n-Electron Materials Project, ERATO, Research Development Corporation of Japan, c/o Matsushita Research, Institute Tokyo, Inc., 3-10-l. Higashimita, Tama-ku, Kawasaki 214, Japan: *Department of Chemistry, Faculty of Engineering, Gunma University, Kiryu, Gunma 376, Japan. Thin films of graphite were formed by chemical vapor deposition using two kinds of precursors, 2, 6-di (2’, 6’ -dimethyl- 1’ naphthoyl)-naphthalene (0) , and 2methyl- 1,2’ naphtylketone (II) . Structures of the films were studied by x-ray diffraction and Raman scattering spectra. The graphite formation temperatures on Ni using (0) and (II) were found to be above 800°C and 6OO”C, respectively. When the dehydrogenation from the starting material is enhanced by Ni below 700 “C, the graphite film could be obtained on the Ni substrate. [TANSO 1996 (No.171) 13-171 Properties of Porous Carbons Prepared from the Wood of Japanese Cypress - Effect of Carbonization Time at 900 “C by Ikuo Abe, Mitsunori Hitomi*, Nobuo Ikuta, Isao Kawafune and Yoshiya Kera*. Osaka Municipal Technical Research Institute, Morinomiya l-650, Joto-ku, Osaka 536, Japan; *Department of Applied Chemistry, Faculty of Science and Engineering, Kinki University, Kowakae, Higashi-Osaka 577, Japan.
In order to obtain basic data for the manufacture of porous carbon materials from various woody wastes, porous carbons were prepared from wood of the Japanese cypress by carbonizing at 900°C and the effect of holding time at 900°C on the properties of the carbons obtained was examined. A slight amount of air entered the vessel for carbonization during the heat treatment at 900°C and an activation reaction occurred and weight loss of the carbon was observed. The weight loss corresponded with the formation of micropores in the carbon. The pore-size distribution curve in the micropore and mesopore ranges of the carbons was similar to that of a commercial activated carbon. An increase of holding time at 900°C caused a development of mesopores. In the macropore range, an increase of holding time at 900°C caused a lowering of the height of the peak at 500nm radius and an increase of the height of the peak at 15OOnm radius. The change of macropore distribution was not appreciably followed by weight change. Porous carbon with a similar
1455
Graphite films with very high crystal perfection were prepared from carbonized aromatic polyimide films by successive heat treatments at 3100°C for 40 min and then 32OO’C for 23 min without mechanical stress. The starting materials were a commercially available Kapton 25 mm in thickness and laboratory prepared high-modulus polyimide films via polyamic acid gel, Crystallinity and 18 and 45 mm in thickness. microtexture of the graphite films were examined by the measurements of x-ray diffraction, maximum transverse magnetoresistance (Dr/r) max and Hall coefficient RH at 4.2 K, and by the observation of electron channeling contrast image (ECI) by scanning electron microscope. The ratios of peak intensities of 101 diffraction peak to 100 diffraction peak, 1101/1100, were 0.000-0.037, mean free path of carriers (1) estimated from (Dr/r) max at 4.2K, O.lT was 5.7-6.5mm , and the mean crystal grain diameter (D) evaluated from EC1 was 11-12mm for the graphite films. A quite large (Dr/r) max was observed at 4.2K for the graphite films. The Shubnikov-de Haas oscillations were also observed clearly at 4.2K in (Drir) max and especially in RH, and the Landau levels of n=2-6 were found. The graphite films obtained can be comparable with an HOPG sample heat treated at 3600°C under high mechanical pressure (HOPG3600) in crystallinity and degree of c-axis orientation of the graphite layers. These results indicate that the crystallinity and c-axis preferred orientation of graphite films can be improved remarkably by extention of the heat treatment time at high temperatures without mechanical stress. There are differences between the electronic properties of HOPG 3600 and those of the graphite films because of their different microtextures i.e. different defect distributions. [TANSO 1996 (No. 17 1) 24-291 Burning-off Characteristics of Carbon Fibers by Joule Heating in Air by Morinobu Endo, Kenji Takeuchi, Yoshiyuki Nishimura and Toshiyuki Kasai Faculty of Engineering, Nagano 380. Japan.
Shinshu
University,
500 Wakasato,
The burning-off characteristics by joule heating of mesophase pitch-based carbon fibers (MPCFs) in air have been studied, in order to evaluate the current
Carbon Vol. 34, No. II, pp. 1455-1458,
1996 Copyright 0 1996 Elsevier Science Ltd Printed in Great Britain. All rights reserved
OOO8-6223/96$15.00 + 0.00
TANS0 Microscopy Studies Carbon on Polished and A. Oberlin.
No. 171 - ABSTRACTS
of Deposition of Pyrolytic Substracts by J.-F. Despres
adsorptive capacity as a commercial activated carbon could be prepared by prolonged heating at 9OO’C. [TANSO 1996 (No. 17 1) 18-231
Laboratoire Marcel Matbieu, UMR 124, CNRS-DRET-UPP Centre Helioparc, 2 avenue du President Pierre Angot-F64000 PAU.
Microtexture and Crystallinity of Highly Crystallized Graphite Films Prepared from Aromatic Polymide Films II - Effect of Extention of Heat Treatment Time at High Temperature by Yutaka Kaburagi, Akira Yoshida, Hideo Kitahata and Yoshihiro Hishiyama
(no abstract supplied)
[TANSO 1996 (No.171) 2-121 Low Temperature Formation of Graphite Thin Films by Chemical Vapor Deposition by Rie Kikuchi, Masako Yudasaka, Takeo Matsui, Yoshimasa Ohki, Etsuro Ota* and Susumu Yoshimura.
Musashi Institute of Technology,
l-28-1, Tamazutsumi,
Setagaya-
ku,Tokyo 158, Japan.
Yoshimura n-Electron Materials Project, ERATO, Research Development Corporation of Japan, c/o Matsushita Research, Institute Tokyo, Inc., 3-10-l. Higashimita, Tama-ku, Kawasaki 214, Japan: *Department of Chemistry, Faculty of Engineering, Gunma University, Kiryu, Gunma 376, Japan. Thin films of graphite were formed by chemical vapor deposition using two kinds of precursors, 2, 6-di (2’, 6’ -dimethyl- 1’ naphthoyl)-naphthalene (0) , and 2methyl- 1,2’ naphtylketone (II) . Structures of the films were studied by x-ray diffraction and Raman scattering spectra. The graphite formation temperatures on Ni using (0) and (II) were found to be above 800°C and 6OO”C, respectively. When the dehydrogenation from the starting material is enhanced by Ni below 700 “C, the graphite film could be obtained on the Ni substrate. [TANSO 1996 (No.171) 13-171 Properties of Porous Carbons Prepared from the Wood of Japanese Cypress - Effect of Carbonization Time at 900 “C by Ikuo Abe, Mitsunori Hitomi*, Nobuo Ikuta, Isao Kawafune and Yoshiya Kera*. Osaka Municipal Technical Research Institute, Morinomiya l-650, Joto-ku, Osaka 536, Japan; *Department of Applied Chemistry, Faculty of Science and Engineering, Kinki University, Kowakae, Higashi-Osaka 577, Japan.
In order to obtain basic data for the manufacture of porous carbon materials from various woody wastes, porous carbons were prepared from wood of the Japanese cypress by carbonizing at 900°C and the effect of holding time at 900°C on the properties of the carbons obtained was examined. A slight amount of air entered the vessel for carbonization during the heat treatment at 900°C and an activation reaction occurred and weight loss of the carbon was observed. The weight loss corresponded with the formation of micropores in the carbon. The pore-size distribution curve in the micropore and mesopore ranges of the carbons was similar to that of a commercial activated carbon. An increase of holding time at 900°C caused a development of mesopores. In the macropore range, an increase of holding time at 900°C caused a lowering of the height of the peak at 500nm radius and an increase of the height of the peak at 15OOnm radius. The change of macropore distribution was not appreciably followed by weight change. Porous carbon with a similar
1455
Graphite films with very high crystal perfection were prepared from carbonized aromatic polyimide films by successive heat treatments at 3100°C for 40 min and then 32OO’C for 23 min without mechanical stress. The starting materials were a commercially available Kapton 25 mm in thickness and laboratory prepared high-modulus polyimide films via polyamic acid gel, Crystallinity and 18 and 45 mm in thickness. microtexture of the graphite films were examined by the measurements of x-ray diffraction, maximum transverse magnetoresistance (Dr/r) max and Hall coefficient RH at 4.2 K, and by the observation of electron channeling contrast image (ECI) by scanning electron microscope. The ratios of peak intensities of 101 diffraction peak to 100 diffraction peak, 1101/1100, were 0.000-0.037, mean free path of carriers (1) estimated from (Dr/r) max at 4.2K, O.lT was 5.7-6.5mm , and the mean crystal grain diameter (D) evaluated from EC1 was 11-12mm for the graphite films. A quite large (Dr/r) max was observed at 4.2K for the graphite films. The Shubnikov-de Haas oscillations were also observed clearly at 4.2K in (Drir) max and especially in RH, and the Landau levels of n=2-6 were found. The graphite films obtained can be comparable with an HOPG sample heat treated at 3600°C under high mechanical pressure (HOPG3600) in crystallinity and degree of c-axis orientation of the graphite layers. These results indicate that the crystallinity and c-axis preferred orientation of graphite films can be improved remarkably by extention of the heat treatment time at high temperatures without mechanical stress. There are differences between the electronic properties of HOPG 3600 and those of the graphite films because of their different microtextures i.e. different defect distributions. [TANSO 1996 (No. 17 1) 24-291 Burning-off Characteristics of Carbon Fibers by Joule Heating in Air by Morinobu Endo, Kenji Takeuchi, Yoshiyuki Nishimura and Toshiyuki Kasai Faculty of Engineering, Nagano 380. Japan.
Shinshu
University,
500 Wakasato,
The burning-off characteristics by joule heating of mesophase pitch-based carbon fibers (MPCFs) in air have been studied, in order to evaluate the current