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Volume 58, Issue 3
March
Displaying 1-12 of 12 articles from this issue
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Paper
Paper
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Masahiro Yasukawa, Yukihiro Hamada, Toshio Kono, Kazushige Ueda, Hiros ...2011 Volume 58 Issue 3 Pages 149-154
Published: 2011
Released on J-STAGE: June 23, 2011
JOURNAL OPEN ACCESSPerovskite-type BaSn1-xCoxO3-δ ceramics were prepared by a solid state reaction, and the electrical conductivity σ and Seebeck coefficient S were measured in the temperature range 373-1073 K to evaluate the thermoelectric power factors S2σ. Dense ceramics with relative densities of ∼98 % were obtained by firing at 1573 K for the BaSn1-xCoxO3-δ with x=0.03-0.15. Temperature dependence of σ and S showed that the BaSn1-xCoxO3-δ ceramics with x=0.03-0.15 were p-type semiconductors. A possible origin of the p-type conduction is hopping of holes between localized states of Co ions. The S2σ values were in the orders of 10-11-10-7 Wm-1K-2 and the highest value was 2.7×10-7 Wm-1K-2 at 1073 K for x=0.15.View full abstractDownload PDF (1087K)
Rapid Communication
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Kiyoshi Mizuuchi, Kanryu Inoue, Yasuyuki Agari, Tohru Nagaoka, Yoshiak ...2011 Volume 58 Issue 3 Pages 155-159
Published: 2011
Released on J-STAGE: June 23, 2011
JOURNAL OPEN ACCESSAluminum nitride (AlN)-particle-dispersed-aluminum (Al) matrix composites were fabricated by Spark Plasma Sintering (SPS) process from the mixture of AlN powders, Al powders and Al-5mass%Si powders. The microstructures, thermal conductivities and thermal expansions of the composites fabricated were examined. These composites were all well consolidated by heating at a temperature range between 798 K and 876 K for 1.56 ks during SPS process. No reaction at the interface between the AlN particle and the Al matrix was observed by scanning electron microscopy for the composites fabricated under the sintering conditions employed in the present study. The relative packing density of the Al/AlN composite fabricated was almost 100 % in a volume fraction range of AlN between 40 % and 60 %. Thermal conductivity of the Al/AlN composite was higher than 180 W/mK at the AlN fraction range between 40 and 65 vol.%, approximately 90 % the theoretical thermal conductivity estimated using Maxwell-Eucken's equation. The coefficient of thermal expansion of the composites falls in the upper line of Kerner's model, indicating strong bonding between the AlN particle and the Al matrix in the composite.View full abstractDownload PDF (1223K) -
Kiyoshi Mizuuchi, Kanryu Inoue, Yasuyuki Agari, Tohru Nagaoka, Yoshiak ...2011 Volume 58 Issue 3 Pages 160-164
Published: 2011
Released on J-STAGE: June 23, 2011
JOURNAL OPEN ACCESSSiC-particle-dispersed-aluminum (Al) matrix composites were fabricated in solid-liquid co-existent state by Spark Plasma Sintering (SPS) process from the mixture of SiC powders, Al powders and Al-5mass%Si powders. The microstructures and thermal conductivities of the composites fabricated were examined. These composites were all well consolidated by heating at a temperature range between 798 K and 876 K for 1.56 ks during SPS process. No reaction at the interface between the SiC particle and the Al matrix was observed by scanning electron microscopy for the composites fabricated under the sintering conditions employed in the present study. The relative packing density of the Al/SiC composite fabricated was higher than 99 % in a volume fraction range of SiC between 40 % and 55 %. Thermal conductivity of the Al/SiC composite increased with increasing the SiC content in the composite in a volume fraction range between 40 and 50 vol.%. The highest thermal conductivity was obtained for Al-50vol.%SiC composite and reached 252 W/mK. The coefficient of thermal expansion of the composites falls in the upper line of Kerner's model, indicating strong bonding between the SiC particle and the Al matrix in the composite.View full abstractDownload PDF (1345K)
Special Issue: Smart Carbon Materials
Summarization
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Akinori Muto2011 Volume 58 Issue 3 Pages 166
Published: 2011
Released on J-STAGE: June 23, 2011
JOURNAL OPEN ACCESSDownload PDF (103K)
Review
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Rika Matsumoto2011 Volume 58 Issue 3 Pages 167-175
Published: 2011
Released on J-STAGE: June 23, 2011
JOURNAL OPEN ACCESSGraphite intercalation compounds (GICs) are one of the classic carbon-related materials. Inserting various atoms or molecules into the interlayer spaces of graphite leads to the formation of GICs, in which the graphite's lattice structure is preserved. Since GICs have certain attractive properties for practical materials such as high electrical conductivities, numerous studies on GICs were carried out around in the 1980's. Today, GIC research continues to be pursued. Especially, the calcium-GIC is the one of the hottest topics in the research fields of carbon material and superconductivity. Here, the fundamentals and the recent topics related to GICs are briefly reviewed.View full abstractDownload PDF (1003K)
Paper
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Takashi Tokue, Kenji Kamishima, Daisuke Miyata, Yuki Sato, Koichi Kaki ...2011 Volume 58 Issue 3 Pages 176-180
Published: 2011
Released on J-STAGE: June 23, 2011
JOURNAL OPEN ACCESSWe have prepared the carbon-based ferromagnets by pyrolytic method under high magnetic field and investigated their crystal structure and magnetic properties. The crystal structure was measured by the synchrotron X-ray diffraction experiment. The diffraction peak of a diamond was observed for the ferromagnetic samples. Thus, the carbon-based ferromagnet can be attributed to the ferromagnetic ordering of radical spins generated by defects in the diamond structure. And, the diffraction peak of a diamond of the ferromagnetic samples increased with the applied magnetic field in sample preparation. Therefore, the magnetic field may help to form a three dimensional ferromagnetic structure in the carbon-based ferromagnet. The highest magnetization was 3.0 emu/g at 300 K for the sample prepared under magnetic field at 6 T.View full abstractDownload PDF (987K) -
Shinichiro Yamamoto, Tatsuya Nakamura, Kenichi Hatakeyama, Mika Hirose ...2011 Volume 58 Issue 3 Pages 181-185
Published: 2011
Released on J-STAGE: June 23, 2011
JOURNAL OPEN ACCESSEM-wave pyramidal-shaped absorbers produced by the traditional smoked roof-tile production process are introduced. In the smoking process, the carbon-coated layer having good electrical conductivity was formed on a dry-shaping pyramid surface made of roof tile clay. It has a superior long-term stability and thermal stability against high power incidence. In this paper, the absorption properties of the absorbers were measured. It is possible to improve the absorption property by controlling the surface resistance of the pyramids. The relationship between EM-wave absorption and surface conductivity are discussed. In addition, pyramidal-shaped absorbers in the millimeter region are developed.View full abstractDownload PDF (1266K) -
Akinori Muto, Youhei Ueno, Yoshinori Ishida2011 Volume 58 Issue 3 Pages 186-190
Published: 2011
Released on J-STAGE: June 23, 2011
JOURNAL OPEN ACCESSPlatinum-porous carbon composite was prepared using a microreactor which could rapidly mix liquids. A 0.8 wt% aqueous solution of alginate acid as a raw carbon material and aqueous solutions of 0.01 M cis-PtCl2(NH3)2 and H2PtCl6 as a raw platinum material were used. These solutions were well mixed through the microreactor without stirring operation. The white yellow solid precipitated by centrifuging was carbonized in a stream of N2. Thus, the platinum-porous carbon composite material was prepared.
The specific surface area of the composite was greater with increasing of heat treatment temperature. The specific surface area was 460∼550 m2/g. In addition, the specific surface area was independent on the flow rate of the feed solutions. It was confirmed by XRD analysis that platinum in the composite was in metallic state. By EDX analysis, platinum metal was confirmed to be well dispersed highly in the porous carbon. About the content of platinum in the composite, cis-PtCl2(NH3) was significantly greater than H2PtCl6. The composite which included the 5 nm platinum particle in diameter was prepared from H2PtCl6 by heat treatment temperature at 500°C.View full abstractDownload PDF (974K) -
Hideki Kume, Yasunori Hasegawa, Toshikazu Nosaka, Yoshikazu Nakayama2011 Volume 58 Issue 3 Pages 191-196
Published: 2011
Released on J-STAGE: June 23, 2011
JOURNAL OPEN ACCESSThe morphology of the carbon nanocoils (CNCs) and their catalyst particles were characterized by a transmission electron microscope (TEM) to discuss the growth mechanism of CNCs. The catalyst particles of CNCs have many corner numbers on TEM images. This means that the catalyst particles of CNCs have several facets. In this study, the growth mechanism of CNCs was discussed at the point of the different velocities of the carbon extrusion from these facets.View full abstractDownload PDF (1695K)
JSPM Announcements
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2011 Volume 58 Issue 3 Pages Pref3_1
Published: 2011
Released on J-STAGE: June 23, 2011
JOURNAL OPEN ACCESSDownload PDF (151K) -
2011 Volume 58 Issue 3 Pages MtgPr3_1-MtgPr3_21
Published: 2011
Released on J-STAGE: June 23, 2011
JOURNAL OPEN ACCESSDownload PDF (644K)
Errata (Vol.58, No.1)
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Hiroshi Kimura, Ryoichi Shimoitani2011 Volume 58 Issue 3 Pages 197
Published: 2011
Released on J-STAGE: June 23, 2011
JOURNAL OPEN ACCESSAbout the paper by Hiroshi Kimura et al. published in the January 2011 issue of the Journal, the authors requested that some errors in the original paper should be corrected.View full abstractDownload PDF (14K)
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