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Volume 2001 (2001)
- Issue 200 Pages 202-
- Issue 199 Pages 155-
- Issue 198 Pages 125-
- Issue 197 Pages 83-
- Issue 196 Pages 1-
Volume 2001, Issue 198
Displaying 1-5 of 5 articles from this issue
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Hirokazu Oda, Tatsuya Tada, Yoshiteru Nakagawa2001 Volume 2001 Issue 198 Pages 125-128
Published: July 28, 2001
Released on J-STAGE: June 28, 2010
JOURNAL FREE ACCESSVarious kinds of electrolytes were removed to utilize the principle of the electric double-layer using the activated carbon electrode. It was easy to be removed in various sulfates and nitrate in the order of alkali metal, alkaline earth metal and transition metal. Though the ammonium salt removed over 75 %, in phosphate and carbonate are hard to be removed. This reason is based on hydrolysis and ion-exchange reaction. In the multicomponent system, it was easy to tend to remove large as electrolyte of the ionic migration speed.View full abstractDownload PDF (1802K) -
Rika Matsumoto, Yoichi Takahashi, Noboru Akuzawa2001 Volume 2001 Issue 198 Pages 129-133
Published: July 28, 2001
Released on J-STAGE: June 28, 2010
JOURNAL FREE ACCESSElectrical conductivities of Cs-unsaturated organic molecule-ternary GIC decrease gradually or rapidly in air, while their thermoelectric powers remain unchanged. For investigating their conductive carriers, electrical conductivity (σ), Hall coefficient (RH) and magnetoresistance (Δρ/ρ) of CsC24 (C2H4) x, CsC24 (C6H6) x and CsC24 (C2H3CN) x were measured, and their carrier concentrations (n) and mobilities (μ) were estimated. The values of RH were negative for all the GICs investigated, thus their dominant carriers were considered to be electrons. On the other hand, thevalues of Δρ/ρ of CsC24 (C2H4) 1.4 were too small to be detected, indicating that its electrical conduction is only throughelectrons, while other GICs have electrons and much less number of holes. These results indicate that all of the ternary GICs investigated maintain a certain fraction of Cs atoms between graphite layers, even after a long time of exposureto air, although some degradation of stage structure are found by XRD as the case of CsC24 (C6H6) 2.1. This consideration corresponds well with the fact that their thermoelectric powers kept unchanged. By observing the change of thegalvanomagnetic properties of the ternary GICs with time, we found that the releasing of part of Cs atoms from theinterlayer nanospace occurred exclusively in the first 30 days.View full abstractDownload PDF (737K) -
Hironori Kakiuchi, Tomohiro Kobayashi, Takayuki Terai2001 Volume 2001 Issue 198 Pages 134-138
Published: July 28, 2001
Released on J-STAGE: June 28, 2010
JOURNAL FREE ACCESSElastic recoil detection analysis (ERDA) is a useful, non-destructive method to determine the hydrogen concentration in several materials. By means of the method, we measured the hydrogen concentration of a diamond-like carbon (DLC) thin film prepared by RF magnetron sputtering method and successfully determined its depth distribution by the comparison of the ERDA spectrum and the DEPTH code calculation. The hydrogen concentration was about 35 at. % and less near the surface region of the DLC thin film, which is in the appropriate concentration range for DLC previously reported. As a result, we confirmed that ERDA is an effective method for measuring hydrogen concentration without destruction.View full abstractDownload PDF (566K) -
Toshiaki Enoki, B. L. V. Prasad2001 Volume 2001 Issue 198 Pages 139-146
Published: July 28, 2001
Released on J-STAGE: June 28, 2010
JOURNAL FREE ACCESSAccording to theoretical predictions, nano-graphite has unique electronic features associated with the cooperation of non-bonding π-electronic state of edge origin (edge state) around the Fermi level (EF), which are entirely different from the electronic properties of ordinary bulk graphite. We investigate the structure and the electronic properties of nano-graphite obtained by heat-treatment-induced conversion from nano-sized diamond particles. The diamond-graphite conversion is completed around HTT of 1600°C, where nano-graphite particles are typically described in terms of polyhedrons with a hole inside and facets consisting of a stacking of 3-7 graphene planes with an in-plane size of ca.3 nm. The density of states at EF, is two orders of magnitudes larger than that of bulk graphite, suggesting an important contribution of the edge states to the electronic features. Intercalation compounds (GIC) with donor (K) and acceptor (Br, I) are prepared. The structure does not have a definite staging feature due to the finite size effect. Interestingly, iodine is found to form GIC, in contrast to bulk graphite that does not give I-GIC. The charge transfer rate becomes reduced in donor GICs in comparison with that of the bulk counterpart, whereas that in acceptor GICs has an opposite trend. The charge transfer makes the role of the edge state less important.View full abstractDownload PDF (1309K) -
[in Japanese]2001 Volume 2001 Issue 198 Pages 147-148
Published: July 28, 2001
Released on J-STAGE: June 28, 2010
JOURNAL FREE ACCESSDownload PDF (391K)
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