| Project/Area Number |
13650713
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| Research Category |
Grant-in-Aid for Scientific Research (C)
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| Allocation Type | Single-year Grants |
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| Section | 一般 |
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| Research Field |
Physical properties of metals
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| Research Institution | University of Tsukuba |
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Principal Investigator |
TANIMOTO Hisanori University of Tsukuba, Institute Materials Science, Assistant Professor, 物質工学系, 助教授 (70222122)
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| Co-Investigator(Kenkyū-buntansha) |
MIZUBAYASHI Hiroshi University of Tsukuba, Institute Materials Science, Professor, 物質工学系, 教授 (40114136)
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| Project Period (FY) |
2001 – 2003
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| Project Status |
Completed (Fiscal Year 2003)
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| Budget Amount *help |
¥2,000,000 (Direct Cost: ¥2,000,000)
Fiscal Year 2003: ¥500,000 (Direct Cost: ¥500,000)
Fiscal Year 2002: ¥1,500,000 (Direct Cost: ¥1,500,000)
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| Keywords | nanocrystalline materials / porous materials / interface effect / nano-filter / gas-deposition method / metallic membrane |
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| Research Abstract |
Metallic films prepared by consolidation of ultra-fine particles may contain nano-size pores and channels along the grain boundaries, and they are expected for the application to metallic nano-filters or catalytic materials. In order to prepare the metallic films containing nano-size channels, low-density nanocrysatlline (n-) Au films were prepared by applying the gas-deposition method. The density of n-Au films prepared was about 93 〜 98 % of the bulk Au density and the mean grain size about 10 〜 20 nm. Some of the n-Au films showed gas-permeability of about 10^<-11> mol m/(Pa m^2 s) for helium gas at room temperature, that is larger by mare than two order than those of the plastic films such as the natural rubber. Pore-like dimples with the diameter of 〜 20 nm were found in the STM surface images of n-Au films with the high gas-permeability. The gas-permeability of the n-Au films was decreased in proportional to the square root of the molecular weight of gas. These observations suggest that the gas-permeability of the present n-Au films is due to the channels with the diameter of 〜 20 nm and the area fraction of 〜 1%, where the gas atoms are assumed to permeate the n-Au films as a molecular flow. Further, the n-Au films with the relative density of 〜 95 % showed a high thermal stability, i.e. the mean grain size remained to be about 40 nm after the annealing at 1200 K for 1.8 ks. It suggests that the nano-channels or pores in the specimens play an important role on the high-thermal stability of the present n-Au films
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