| Project/Area Number |
63460061
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| Research Category |
Grant-in-Aid for General Scientific Research (B)
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| Allocation Type | Single-year Grants |
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| Research Field |
Applied materials
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| Research Institution | Okayama University of Science |
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Principal Investigator |
HASHIMOTO Hatsujiro Okayama University of Science Faculty of Engineering. Professor, 工学部, 教授 (30027726)
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| Co-Investigator(Kenkyū-buntansha) |
YOKOTA Yasuhiro Okayama University of Science Faculty of Science. Lecture, 理学部, 講師 (50200902)
SUKEDAI Eiichi Okayama University of Science Faculty of Engineering. Professor, 工学部, 教授 (00090217)
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| Project Period (FY) |
1988 – 1989
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| Project Status |
Completed (Fiscal Year 1989)
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| Budget Amount *help |
¥6,000,000 (Direct Cost: ¥6,000,000)
Fiscal Year 1989: ¥2,200,000 (Direct Cost: ¥2,200,000)
Fiscal Year 1988: ¥3,800,000 (Direct Cost: ¥3,800,000)
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| Keywords | phase transformation / Zeolite radiation damage / electron energy loss spectroscopy / observation of atomic movement in crystals / high Tc superconductor / Atomic level electron microscopy / Charge Density Waves (CDW) phase transformation / Shape memory alloy phase transformation / 照射損傷 / ゼオライト / 電子エネルギ損失スペクトル / 原子レベル電子顕微鏡 / 電荷密度波CDW / 高Tc超伝導材料 / 極低温高分解能電顕試料ホルダー / 電荷密度波 / CDW / Nb_3Sn超伝導材料 / 動的観察 |
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| Research Abstract |
The present research aimed to study the structure change of various materials in atomic scale at various temperature including very low temperature by using atom resolution electron microscopes with the accelerating voltage of 2OOkV, 4OOkV, 8OOkV, which have low temperature specimen stages of liquid helium and liquid nitrogen temperature and an electron energy loss spectrometer. The images were recorded by using GATAN TV camera and Sony TV monitor as well as photographic method.
The following observations have been carried out.
1. Observation of the atomic structure of Nb_3Sn superconductor at liq.-He and room temperature. Similar observations are carried out for the ceramic super conducting materials with high critical temperature Tc i.e. Y.Ba_2Cu_3O_x, ErBa_2Cu_3O_x, Bi_2Sr_2CaCu_2O_x(85K), and Bi_2Ca_2Cu_3O_x(110K).
2. Long chain molecules containing heavy atom Th were supported on graphite thin films and observed in the 2OOkV electron microscope with superconducting objective lens, wh
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ich lower the specimen temperature to be at liq.-He temperature. It was observed that even at the liq.-He temperature, bright spots images of Th atoms in the dark field still moved under the irradiation of 2OOkV electrons.
3.1T-TaS_2 and In_xNb_3 Te_4 (X=1.3-1.5) which produce the periodic lattice distortion due to Charge Density Wave were observed at room and liq.-He temperature by 2OOkV electron microscope and their phase transformation were observed in electron diffraction patterns and electron micrographs.
4. Radiation damage effect of Zeolite crystal, which shows heavy damage at low temperature was studied at room and low temperatures by an 2OOkV electron microscope with electron energy analyzer. It was noted that even the specimen crystal changes to amorphous, water in crystal are still in the specimen and disappear together with Ca-atoms some minutes later. This phenomena was interpreted by the escape of water and Ca ions in channels of zeolite structure at the same time.
5. In order to investigate displacement of atoms and radiation effect under high energy electron irradiation, lMeV Atom Resolution Electron Microscope in California University and 4OOkV one in Okayama were used to see the behavior of Si and Th atoms in crystals and molecules respectively.
6. Atomic arrangements and defects structure of Ni Ti shape memory alloy at above and below of the phase transformation temperature were studied by a specimen heating device. The atomic structure of the boundary of two phases and the structure change of repeating twins in every cycle of elevation of the temperature are observed. Less
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