| Project/Area Number |
59470001
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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 |
物理化学一般
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| Research Institution | College of Arts and Sciences, University of Tokyo |
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Principal Investigator |
NISHIKAWA Masaru University of Tokyo, College of Arts and Sciences, 教養部, 教授 (10012329)
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| Co-Investigator(Kenkyū-buntansha) |
HATANO Akira University of Tokyo, College of Arts and Sciences, 教養学部, 助手 (10012395)
NAKAGAWA Kazumichi University of Tokyo, College of Arts and Sciences, 教養学部, 助手 (00134403)
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| Project Period (FY) |
1984 – 1986
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| Project Status |
Completed (Fiscal Year 1986)
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| Budget Amount *help |
¥7,100,000 (Direct Cost: ¥7,100,000)
Fiscal Year 1986: ¥300,000 (Direct Cost: ¥300,000)
Fiscal Year 1985: ¥500,000 (Direct Cost: ¥500,000)
Fiscal Year 1984: ¥6,300,000 (Direct Cost: ¥6,300,000)
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| Keywords | Electron mobility / Dense gases / 超臨界状態 / 準自由状態エネルギー / 伝導状態エネルギー |
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| Research Abstract |
The mobility <mu> and the conducting state energy Vo of excess electrons in supercritical n-(n-B), isobutane(i-B), n-(n-P), iso-(i-P) and neopentane(neoP) were measured as a function of density N, With increase in N,the density-normalized mobility <mu> N in all hydrocarbons studied goes through a minimum at a density below the respective critical density, and then increases to a maximum. Vo values initially decrease from zero at N=0, and then increase wth N. Raising temperature causes <mu> N minima to shift toward lower N in all hydrocarbons, but the maxima shift to lower N only in n-B and in n-P. In other more symmetrical hydrocarbons the loci of maxima are independent of temperature. The minima in n-B and n-P including temperature dependence is adequately reproduced by the Cohen-Lekner model with the use of the structure factor estimated from the speed of sound. In i-B,i-P and neoP the model predicts the occurrence of the minima at a higher densities than are observed, and changes in the magnitude of scattering cross section with N have to be invoked, In these hydrocarbons the correspondence of Vo minima and <mu> N maxima is observed, which indicates that the minima of the deformation potentials are the cause for the appearance of the maxima. The maxima in the straight-chain hydrocarbons are due to the transition from the quasifree to the localized electron states caused by the increased importance at higher densities of fluctuations in coordination numbers and orientations of unsymmetrical molecules. The next step of the study of excess electrons in dielectric media is to investigate <mu> and Vo behavior in a still higher density region (under high pressure) with the aim to gather information concerning the nature of localized states.
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