1993 Fiscal Year Final Research Report Summary
Concurrent Effects of Electronic and Lattia Excitations and Electric Field on Electrical Conductirity
| Project/Area Number |
04650601
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| Research Category |
Grant-in-Aid for General Scientific Research (C)
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| Allocation Type | Single-year Grants |
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| Research Field |
Physical properties of metals
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| Research Institution | KYUSHU UNIVERSITY |
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Principal Investigator |
KINOSHITA Chiken Kyushu University, Department of Nuclear Engineering, Professor, 工学部, 教授 (50037917)
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| Co-Investigator(Kenkyū-buntansha) |
SHIIYAMA Ken-ichi Kyushu University, Department of Nuclear Engineering, Research Associate, 工学部, 助手 (30243900)
TOMOKIYO Yoshitsugu Kyushu University, Research Laboratory of HVEM, Associate Professor, 工学部, 助教授 (40037891)
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| Project Period (FY) |
1992 – 1993
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| Keywords | Ceramics / Radiation Effect / Electrical Conductivity / Electronic Excitation / Displacement Damage / Electric Field / Fusion Materials / High Voltage Electron Microscopy |
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| Research Abstract |
The first objective of the present project lies on the establishment of the method for measuring the electrical conductivity in a high voltage electron microscope. The second objective is to get insights into the concurrent effect of electronic and lattice excitation on the nucleation and growth process of defect clusters and electrical properties such as electrical conductivity(sigma) and dielectric loss tangent(tan delta) in ceramic materials. The results obtained are as follows ; 1. A method for measuring the electrical conductivity during irradiation with electrons and ions under electric field was established and was confirmed to defect sigma and tan delta higher than 2 x 10^<-5>/OMEGA/m and 1 x 10^<-4>, respectively. The values of sigma and tan delta for ZrO_2-3%Y_2O_3 and MgO increased at temperatures between 300 and 800 K under irradiation with 1000 keV electrons, showing their enhancement. More systematic e4experiments are required to get conclusive remarks on the mechanism of the irradiation enhancement of those electrical properties. 2. The concurrent effect of 1000 keVelectrons on cascade damages induced by 30 keV He^+, Ar^+ or Xe^+ ions was defected as a retardation of the accumulation of cascade damages in Si and Ge and as the enhancement of the nucleation and growth of defect clusters in MgO-nAl_2O_3.3. The importance of electric field was confirmed for describing the nucleation and growth process as well as the electrical properties during irradiation. A set of kinetic equation was established for describing the concurrent effect of irradiation and electric field on the nucleation and growth process of defect clusters.
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