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Volume 1970 (1970)
- Issue 63 Pages 110-
- Issue 62 Pages 80-
- Issue 61 Pages 42-
- Issue 60 Pages 2-
Volume 1970, Issue 60
Displaying 1-5 of 5 articles from this issue
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Michio Inagaki, Takuro Tsuzuku1970 Volume 1970 Issue 60 Pages 2-7
Published: March 25, 1970
Released on J-STAGE: June 28, 2010
JOURNAL FREE ACCESSAnnealing effects on the X-ray diffraction profiles of a neutron-irradiated graphite dosed to 7.2×1020nvt (Ni) were studied. The stepwise annealing was performed at various temperatures between 800 and 2300 °C for 60 min. under the reduced pressure of about 10-2 Torr.
The (00l) diffraction lines were observed to shift gradually to higher angle side with the increase in annealing temperature, accompanied by sharpening of the profiles themselves. The dependence of apparent co-spacing measured from (002) line on the annealing time was very similar to those found for soft carbons on their graphitization process. Three-dimensional diffraction line (112) was observed after the annealing above 1200°C. These results are consistent with the behaviors of electronic and mechanical properties obtained for the same kind specimen of neutron-irradiated graphite.
Both (002) and (004) diffraction profiles were unsymmetrical up to the annealing temperature of 1400°C. However, (004) profile was apparently less unsymmetrical than (002), and co-spacing obtained from (004) profile was always less than that from peak position of (002). This fact seems to suggest that the irradiated graphite on annealing process consists of multiple structural components, which have different concentration of some imperfections (for example, displacement of carbon atoms from graphite-like layer plane), and produce different contributions to (002) and (004) reflections. Based upon this assumption, a graphical separation of the observed (002) profile into two structural components was examined.View full abstractDownload PDF (913K) -
Yoichi Takahashi, Katsuki Miyauchi, Takashi Mukaibo1970 Volume 1970 Issue 60 Pages 8-11
Published: March 25, 1970
Released on J-STAGE: June 28, 2010
JOURNAL FREE ACCESSThe thermal expansion behavior of the interlayer spacings of artificial graphite and graphite-bromine residue compounds was investigated by using a high temperature X-ray diffractometer at temperatures between room temperature and 800°C.
The c-spacing of the artificial graphite sample used was confirmed to have an almost linear thermal expansion up to 800°C, and the calculated linear expansion coefficient agreed well with the values in literatures. On the other hand, an anomalous hysteresis was observed on the graphite-bromine residue compound (1.2 atm. % bromine). At room temperature, the c-spacing of the residue compound was a little larger than that of the graphite. When the temperature was increased, the normal expansion of the c-spacing of the residue compound showed a break at about 330°C, and apparently negative thermal expansion (contraction) was observed up to 500°C. Over this temperature, the c-spacing of the residue compound became nearly equal to that of the graphite. On cooling, the anomaly on reverse direction occured at temperatures between 330°C and 200°C.
The observed behavior is explained as follows: the bromine molecules, which would exist in the interstices of graphite layers at lower temperatures, would become unstable above 330°C and would migrate from the interstices to crystal imperfections. This trans formation would proceed reversibly on cooling with some hysteresis.View full abstractDownload PDF (202K) -
[in Japanese]1970 Volume 1970 Issue 60 Pages 12-20
Published: March 25, 1970
Released on J-STAGE: June 28, 2010
JOURNAL FREE ACCESSDownload PDF (1044K) -
[in Japanese]1970 Volume 1970 Issue 60 Pages 21-30
Published: March 25, 1970
Released on J-STAGE: June 28, 2010
JOURNAL FREE ACCESSDownload PDF (1528K) -
[in Japanese]1970 Volume 1970 Issue 60 Pages 30-38
Published: March 25, 1970
Released on J-STAGE: June 28, 2010
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