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150. Interfacial electrical properties of amorphous, d.c. sputter-deposited carbon films on crystalline silicon
220
Abstracts
141. Structural
and electrical
properties of SbCl<
intercalated graphite fibers
A. Hazratti, C. H. Olk and P. C. Eklund (Uniuersity of Kentucky, Department of Physics and Astronomy, Lexington, KY 40506, U.S.A.). No short abstract received. 142. Low resistivity intercalated pitch based carbon fibers V. Nataragan and J. A. Woolam (University of Nebraska, Department of Electrical Engineering, Lincoln, NB 68588, U.S.A.). A. Yavrouian (Jet Propulsion Laboratory, Pasadena, CA 91109, U.S.A.).
We have intercalated carbon fibers from various sources with both single and “double” species. These include Br,, Br, followed by HN03, Br, followed by SbCl,, ICI, ICl followed by SbCl,, and ICI followed by HNO,. Electrical resistivity, magnetoresistance, thermal and air stability, as well Shubnikov-deHaas measurements have been made. 143. An unusual resistivity maximum in low modulus carbon fibers (Celanese Research Company, Summit, NJ 07901, U.S.A.). I. L. Spain and K. J. Volin (Physics Department, Colorado State University, Ft. Collins, CO 80523, U.S.A.). An
H. A. Goldberg
and I. L. Kalnin
unusual maximum has been found in the temperature dependence of the resistivity of several low modulus PAN-based carbon fibers. Correlations between this resistivity behavior and other physical properties (Young’s modulus, strain to fracture, etc.) have been studied and the results will be reported.
magnitude larger than in graphite) determined Hall measurements, are found in these films.
by
146. Optical properties of hydrogenated amorphous carbon films produced by plasma CVD of propane Y. Ichinose and F. Shimokawa (Technological University of Nagaoka, 1603-1, Kami-tomioka, Nagaoka, Niigata, 949-54, Japan). In the present paper, we
investigated on the optical, electrical and structural properties of hydrogenated amorphous carbon (a-C : H) films prepared from propane (C,H,) gas by the plasma CVD method. It was found that a-C:H films obtained here have very large values of 3.1 eV in the optical gap energy and show very bright white-blue photoluminescence with a peak energy of 2.75 eV. These values are the maximum. 147. Optical properties of r.f. plasma deposited and ion beam deposited amorphous carbon films
D. Mathine, A. Azim Khan, G. Bu-Abbud, J. A. Woollam, B. A. Banks and S. Domitz (University of Nebraska-Lincoln, Department of Electrical Engineering, W194 Nebraska Hall, Lincoln, NE 68588, U.S.A.). We have used ion beam sputtering and
plasma deposition to prepare diamond-like carbon films on silicon, gallium arsenide and silica glass. We have measured the optical dielectric constant and extinction coefficient in the visible spectrum, and have evaluated the interface electrical properties with semiconductors using high frequency conductance measurements. The effects of annealing on electrical, optical and structural properties are discussed.
144. Magnetoresistance and microstructure of carbonfiber/CVD-earbon composites Y. Hishiyama and Y. Kaburagi (Musashi Institute of Technology, Setagaya-ku, Tokyo, 158, Japan). T. Hagio (Government Industrial Research Institute of Kyushu, Shuku-machi, Tosu-shi, 841, Japan). E. Yasuda, Y. Tanabe and S. Kimura (Research Labora-
148. Use of Raman scattering to investigate disorder and crystallite formation in AS-deposited and annealed carbon films R. 0. Dillon and John A. Woollam (Department of Electrical Engineering, University of Nebraska, Lincoln, NE 68588, U.S.A.). No short abstract received.
tory of Engineering Materials, Tokyo Institute of Technology, Midori-ku, Yokohama-shi, 227, Japan).
149. X-Ray photoelectron and Auger spectra of AS-
Carbon-fiber/CVD-carbon composites were made by chemical vapor deposition of propane-hydrogen mixtures at 1300°C. Three types of matrix components were obtained. Magnetoresistance was measured at 4.2 K for these components and for those heattreated to 1400°C. The data reflect microstructures of the matrix components. The results are in agreement with those of the optical microscope observations. 145. Hall measurements of metallic carrier densities in ion irradiated amorphous carbon films
T. Venkatesan, R. C. Dynes, A. E. White, B. J. Wilkens, J. M. Gibson and R. Hamm (Bell Laboratories, Murray Hill, NJ 07974, U.S.A.). Amorphous carbon films irradiated with 2 MeV Ar+ ions (at a dose of 10” ions/cm’) exhibit a decrease in resistivity from 5 x lo-* 52cm to 5 x 10m4Q cm. Carrier densities of N 1O23electrons/cm’ (four to five orders of
deposited and annealed R.F. and LB. deposited carbon films? David Liu (NASA Lewis Research Center, Cleveland, OH 44135, U.S.A.). R. 0. DillonS and John A. Woollam (Department of Electrical Engineering, University of Nebraska, Lincoln, NE 68588, U.S.A.). No
short abstract received. TResearch supported by the NASA Lewis Research Center, Cleveland, OH 44135, U.S.A. $On leave from the University of Waikato, Hamilton, New Zealand. 150. Interfacial electrical properties of amorphous, d.c. sputter-deposited carbon films on crystalline silicon A. Azim Khan and John A. Woollam (Department of Electrical Engineering, University of Nebraska, Lincoln, NE 68588, U.S.A.). Yun Chung (Universal
Abstracts Energy Systems, Dayton. short abstract received.
OH
45432,
U.S.A.).
No
151. Spin carbo+polymer composites B. Jachym, I. Witort and G. Wisniewski (Institute of Physics, Technical University, ul. Majakowskiego 1 l/12. 80-952 Gdansk, Poland). Conducting structures formed during radical polymerization as a result of recombination of polyester resin macroradicals and unpaired spins of acetylene carbon black are the source of interesting electronic properties. Such compositions are distinguished by metallic character of electrical conduction and increased mechanical strength. Compositions of that type may find many practical applications and also are an example which enables understanding phenomena related to other domains of science.
152. Morphology and electrical properties of carbon black grafted with vinyl monomers Shin’nosuke Miyauchi (Technological University of Nagaoka, NagaokalJapan). Kumakazu Ohkita University, of Engineering, Niigata (Faculty NiigatalJapan). Yoshio Sorimachi, Eiki Togashi and Ichiro Tsubata (Technological University of Nagaoka, NagaokaiJapan). Carbon black was grafted with comonomers consisting of methyl methacrylate and glycygyl methacrylate. Then, resistors were made by coating the grafted carbon on a plate and being cured with diamine. It was found from morphological and electrical properties that carbon black are rearranged in curing, resulting in an increase in conductivity.
153. Some application of graphite intercalation compounds to conducting polymers F. L. Vogel (Moore School 02, University of Pennsylvania, Philadelphia, PA 19104, U.S.A.). No short abstract received.
VII. SURFACE
SCIENCE
154. Microporosity and adsorption properties of carbonaceous adsorbents M. M. Dubinin (Institute of Physical Chemistry, U.S.S.R. Academy of Sciences). Two new independent methods for determining the geometrical surface area of micropore walls of carbonaceous adsorbents have been proposed. Their satisfactory agreement has been substantiated experimentally. An analysis of benzene adsorption isotherms has been carried out on model carbonaceous microand supermicroporous adsorbents with different structural parameters and on nonporous or mesoporous adsorbents with equal geometrical surface areas. A quantitative estimate of the increase of adsorption values in micro- and supermicropores with nonporous and mesoporous adsorbents under similar conditions has been given for the first time.
221
155. The reaction of activated carbons with carbon dioxide and its effect on their porous texture J. M. Martin-Martinez, A. Mendez, M. Molina and F. Rodriguez-Reinoso (Departamento de Quimica Inorganica, Universidad de Alicante, Alicante, Spain). J. de D. Lopez-Gonzalez (Departamento de Q&mica In organica, U.N.E.D., Madrid, Spain). Two activated carbons prepared from almond shells and olive stones have been reacted with CO2 at 1098 K for different periods of time to obtain two series of carbons with a wide range of burn-off. The microporosity of the carbons has been studied by adsorption of N,, CO,, n-butane, bencene, n-hexane, cyclohexane and 2-2 dymethylbutane and using different methods of analysis. The pore volume increases regularly upon gasification, this being a very different behaviour in respect to that found in the reaction of the same carbons with air at 623 K. 156. Effect of activated carbon pore structure on dynamic adsorption zone A. J. Juhola (MSA Research Corporation, Evans City, PA 16033, U.S.A.). An equation was developed which relates the activated carbon’s pore structure and the operating variables to the adsorption zone length and concentration profile in the carbon when an acetone laden airstream is passed through the bed. The studies were conducted on seven carbons, at seven different concentrations, three sieve sizes, three flow rates and three temperatures. 157. Surface area/monolayer capacity or limiting micropore volume of carbons from binary and ternary mixtures P. T. John, K. C. Nagpal and D. K. Suri (X-rays Section, Specialised Techniques Division, National Physical Laboratory, New Delhi, 110012, India). One can calculate surface area of mesoporous materials or limiting micropore volume of microporous materials from binary and ternary mixture adsorption found by means of mixture adsorption isotherm developed using the constants of John’s pure component adsorption isotherms. Equations of Lewis et al. is used to determine the contribution of each component of the mixture. 158. Residual adsorption capacity of carbon beds Leonard A. Jones and Eric B. Sansone (NCIFrederick Cancer Research Facility, Frederick, M.D. 21701, U.S.A.). Retention times of small (~0.3 ml) ethane pulses in packed beds (l-3 g) of activated carbon granules were studied as a function of bed weight, flowrate, and percent bed saturation, using Ccl, vapor or moisture as carbon contaminants. Linear relations were found between the logarithm of normalized reduced time parameters and the residual adsorption capacity of the bed. 159. Adsorption studies of strontium on activated carbons from aqueous solutions J. Rivera-Utrilla, M. A. Ferro-Garcia and A.
Abstracts
141. Structural
and electrical
properties of SbCl<
intercalated graphite fibers
A. Hazratti, C. H. Olk and P. C. Eklund (Uniuersity of Kentucky, Department of Physics and Astronomy, Lexington, KY 40506, U.S.A.). No short abstract received. 142. Low resistivity intercalated pitch based carbon fibers V. Nataragan and J. A. Woolam (University of Nebraska, Department of Electrical Engineering, Lincoln, NB 68588, U.S.A.). A. Yavrouian (Jet Propulsion Laboratory, Pasadena, CA 91109, U.S.A.).
We have intercalated carbon fibers from various sources with both single and “double” species. These include Br,, Br, followed by HN03, Br, followed by SbCl,, ICI, ICl followed by SbCl,, and ICI followed by HNO,. Electrical resistivity, magnetoresistance, thermal and air stability, as well Shubnikov-deHaas measurements have been made. 143. An unusual resistivity maximum in low modulus carbon fibers (Celanese Research Company, Summit, NJ 07901, U.S.A.). I. L. Spain and K. J. Volin (Physics Department, Colorado State University, Ft. Collins, CO 80523, U.S.A.). An
H. A. Goldberg
and I. L. Kalnin
unusual maximum has been found in the temperature dependence of the resistivity of several low modulus PAN-based carbon fibers. Correlations between this resistivity behavior and other physical properties (Young’s modulus, strain to fracture, etc.) have been studied and the results will be reported.
magnitude larger than in graphite) determined Hall measurements, are found in these films.
by
146. Optical properties of hydrogenated amorphous carbon films produced by plasma CVD of propane Y. Ichinose and F. Shimokawa (Technological University of Nagaoka, 1603-1, Kami-tomioka, Nagaoka, Niigata, 949-54, Japan). In the present paper, we
investigated on the optical, electrical and structural properties of hydrogenated amorphous carbon (a-C : H) films prepared from propane (C,H,) gas by the plasma CVD method. It was found that a-C:H films obtained here have very large values of 3.1 eV in the optical gap energy and show very bright white-blue photoluminescence with a peak energy of 2.75 eV. These values are the maximum. 147. Optical properties of r.f. plasma deposited and ion beam deposited amorphous carbon films
D. Mathine, A. Azim Khan, G. Bu-Abbud, J. A. Woollam, B. A. Banks and S. Domitz (University of Nebraska-Lincoln, Department of Electrical Engineering, W194 Nebraska Hall, Lincoln, NE 68588, U.S.A.). We have used ion beam sputtering and
plasma deposition to prepare diamond-like carbon films on silicon, gallium arsenide and silica glass. We have measured the optical dielectric constant and extinction coefficient in the visible spectrum, and have evaluated the interface electrical properties with semiconductors using high frequency conductance measurements. The effects of annealing on electrical, optical and structural properties are discussed.
144. Magnetoresistance and microstructure of carbonfiber/CVD-earbon composites Y. Hishiyama and Y. Kaburagi (Musashi Institute of Technology, Setagaya-ku, Tokyo, 158, Japan). T. Hagio (Government Industrial Research Institute of Kyushu, Shuku-machi, Tosu-shi, 841, Japan). E. Yasuda, Y. Tanabe and S. Kimura (Research Labora-
148. Use of Raman scattering to investigate disorder and crystallite formation in AS-deposited and annealed carbon films R. 0. Dillon and John A. Woollam (Department of Electrical Engineering, University of Nebraska, Lincoln, NE 68588, U.S.A.). No short abstract received.
tory of Engineering Materials, Tokyo Institute of Technology, Midori-ku, Yokohama-shi, 227, Japan).
149. X-Ray photoelectron and Auger spectra of AS-
Carbon-fiber/CVD-carbon composites were made by chemical vapor deposition of propane-hydrogen mixtures at 1300°C. Three types of matrix components were obtained. Magnetoresistance was measured at 4.2 K for these components and for those heattreated to 1400°C. The data reflect microstructures of the matrix components. The results are in agreement with those of the optical microscope observations. 145. Hall measurements of metallic carrier densities in ion irradiated amorphous carbon films
T. Venkatesan, R. C. Dynes, A. E. White, B. J. Wilkens, J. M. Gibson and R. Hamm (Bell Laboratories, Murray Hill, NJ 07974, U.S.A.). Amorphous carbon films irradiated with 2 MeV Ar+ ions (at a dose of 10” ions/cm’) exhibit a decrease in resistivity from 5 x lo-* 52cm to 5 x 10m4Q cm. Carrier densities of N 1O23electrons/cm’ (four to five orders of
deposited and annealed R.F. and LB. deposited carbon films? David Liu (NASA Lewis Research Center, Cleveland, OH 44135, U.S.A.). R. 0. DillonS and John A. Woollam (Department of Electrical Engineering, University of Nebraska, Lincoln, NE 68588, U.S.A.). No
short abstract received. TResearch supported by the NASA Lewis Research Center, Cleveland, OH 44135, U.S.A. $On leave from the University of Waikato, Hamilton, New Zealand. 150. Interfacial electrical properties of amorphous, d.c. sputter-deposited carbon films on crystalline silicon A. Azim Khan and John A. Woollam (Department of Electrical Engineering, University of Nebraska, Lincoln, NE 68588, U.S.A.). Yun Chung (Universal
Abstracts Energy Systems, Dayton. short abstract received.
OH
45432,
U.S.A.).
No
151. Spin carbo+polymer composites B. Jachym, I. Witort and G. Wisniewski (Institute of Physics, Technical University, ul. Majakowskiego 1 l/12. 80-952 Gdansk, Poland). Conducting structures formed during radical polymerization as a result of recombination of polyester resin macroradicals and unpaired spins of acetylene carbon black are the source of interesting electronic properties. Such compositions are distinguished by metallic character of electrical conduction and increased mechanical strength. Compositions of that type may find many practical applications and also are an example which enables understanding phenomena related to other domains of science.
152. Morphology and electrical properties of carbon black grafted with vinyl monomers Shin’nosuke Miyauchi (Technological University of Nagaoka, NagaokalJapan). Kumakazu Ohkita University, of Engineering, Niigata (Faculty NiigatalJapan). Yoshio Sorimachi, Eiki Togashi and Ichiro Tsubata (Technological University of Nagaoka, NagaokaiJapan). Carbon black was grafted with comonomers consisting of methyl methacrylate and glycygyl methacrylate. Then, resistors were made by coating the grafted carbon on a plate and being cured with diamine. It was found from morphological and electrical properties that carbon black are rearranged in curing, resulting in an increase in conductivity.
153. Some application of graphite intercalation compounds to conducting polymers F. L. Vogel (Moore School 02, University of Pennsylvania, Philadelphia, PA 19104, U.S.A.). No short abstract received.
VII. SURFACE
SCIENCE
154. Microporosity and adsorption properties of carbonaceous adsorbents M. M. Dubinin (Institute of Physical Chemistry, U.S.S.R. Academy of Sciences). Two new independent methods for determining the geometrical surface area of micropore walls of carbonaceous adsorbents have been proposed. Their satisfactory agreement has been substantiated experimentally. An analysis of benzene adsorption isotherms has been carried out on model carbonaceous microand supermicroporous adsorbents with different structural parameters and on nonporous or mesoporous adsorbents with equal geometrical surface areas. A quantitative estimate of the increase of adsorption values in micro- and supermicropores with nonporous and mesoporous adsorbents under similar conditions has been given for the first time.
221
155. The reaction of activated carbons with carbon dioxide and its effect on their porous texture J. M. Martin-Martinez, A. Mendez, M. Molina and F. Rodriguez-Reinoso (Departamento de Quimica Inorganica, Universidad de Alicante, Alicante, Spain). J. de D. Lopez-Gonzalez (Departamento de Q&mica In organica, U.N.E.D., Madrid, Spain). Two activated carbons prepared from almond shells and olive stones have been reacted with CO2 at 1098 K for different periods of time to obtain two series of carbons with a wide range of burn-off. The microporosity of the carbons has been studied by adsorption of N,, CO,, n-butane, bencene, n-hexane, cyclohexane and 2-2 dymethylbutane and using different methods of analysis. The pore volume increases regularly upon gasification, this being a very different behaviour in respect to that found in the reaction of the same carbons with air at 623 K. 156. Effect of activated carbon pore structure on dynamic adsorption zone A. J. Juhola (MSA Research Corporation, Evans City, PA 16033, U.S.A.). An equation was developed which relates the activated carbon’s pore structure and the operating variables to the adsorption zone length and concentration profile in the carbon when an acetone laden airstream is passed through the bed. The studies were conducted on seven carbons, at seven different concentrations, three sieve sizes, three flow rates and three temperatures. 157. Surface area/monolayer capacity or limiting micropore volume of carbons from binary and ternary mixtures P. T. John, K. C. Nagpal and D. K. Suri (X-rays Section, Specialised Techniques Division, National Physical Laboratory, New Delhi, 110012, India). One can calculate surface area of mesoporous materials or limiting micropore volume of microporous materials from binary and ternary mixture adsorption found by means of mixture adsorption isotherm developed using the constants of John’s pure component adsorption isotherms. Equations of Lewis et al. is used to determine the contribution of each component of the mixture. 158. Residual adsorption capacity of carbon beds Leonard A. Jones and Eric B. Sansone (NCIFrederick Cancer Research Facility, Frederick, M.D. 21701, U.S.A.). Retention times of small (~0.3 ml) ethane pulses in packed beds (l-3 g) of activated carbon granules were studied as a function of bed weight, flowrate, and percent bed saturation, using Ccl, vapor or moisture as carbon contaminants. Linear relations were found between the logarithm of normalized reduced time parameters and the residual adsorption capacity of the bed. 159. Adsorption studies of strontium on activated carbons from aqueous solutions J. Rivera-Utrilla, M. A. Ferro-Garcia and A.