| Project/Area Number |
11640579
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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 |
機能・物性・材料
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| Research Institution | Yokohama National University |
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Principal Investigator |
MIZUGUCHI Jin Tokohama National University, Faculty of Engineering, Professor, 工学部, 教授 (90281005)
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| Project Period (FY) |
1999 – 2000
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| Project Status |
Completed (Fiscal Year 2000)
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| Budget Amount *help |
¥3,500,000 (Direct Cost: ¥3,500,000)
Fiscal Year 2000: ¥1,500,000 (Direct Cost: ¥1,500,000)
Fiscal Year 1999: ¥2,000,000 (Direct Cost: ¥2,000,000)
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| Keywords | Organic pigment / Thermochromism / Crystal structure / Electronic structure / Intermolecular interaction / Perylene / Pyrrolopyrrole / Indigo / 光記録 / 電子スペクトル / X線回折 / 赤外線吸収スペクトル / 相転移 / 光ディスク |
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| Research Abstract |
Thermochromic properties of perylene-black pigments have been characterized, with special attention to potential applications for optical disks, from the standpoint of molecular and crystal structures as well as intermolecular interactions. Thermochromism is found not to arise from changes in molecular structure but due to changes in intermolecular interactions under temperature variations. The perylene-black pigments investigated are characteristic of the typical systems, in which the interactions between transition dipoles prevail in the solid state due to large absorption coefficients of the constituent molecules. In this case, there appear two absorption bands in the visible region : one is attributed to individual molecules (473 nm) and the other is due to exciton coupling effects (635 nm). Since the latter band depends on the intermolecular interactions, the present band exhibits a remarkable temperature dependence. This is the mechanism of the thermochromism of the perylene black. In an extreme case, the color changes between red ("amorphous") and black ("crystalline"). This color change can be applied to optical disk systems based on an AlGaInP diode laser of 635 nm. An information storage system has been developed in which the absorption at 635 nm is switched on (red→black) or switched-off (black→red) on irradiation with laser in the presence of a hydrazone compound that induces a phase change.
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