1988 Fiscal Year Final Research Report Summary
THE INFRARED AND FAR-INFRARED POLARIZED REFLECTANCE SPECTRA OF ORGANIC CONDUCTORS. MICROSPECTOROPHOTOMETORIC STUDY
| Project/Area Number |
61430003
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| Research Category |
Grant-in-Aid for General Scientific Research (A)
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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 | TOKYO METROPOLITAN UNIVERSITY |
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Principal Investigator |
IKEMOTO Isao TOKYO METROPOLITAN UNIVERSITY, FACULTY OF SCIENCE, PROFESSOR, 理学部, 教授 (00011601)
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| Co-Investigator(Kenkyū-buntansha) |
SAITO Kazuya TOKYO METROPOLITAN UNIVERSITY, FACULTY OF SCIENCE, SENIOR RESEARCH ASSOCIATE, 理学部, 助手 (30195979)
KIKUCHI Koichi TOKYO METROPOLITAN UNIVERSITY, FACULTY OF SCIENCE, SENIOR RESEARCH ASSOCIATE, 理学部, 助手 (40177796)
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| Project Period (FY) |
1986 – 1988
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| Keywords | ORGANIC SUPERCONDUCTOR / RADICAL SALT / DMET / 反射スペクトル / 電気伝導度 |
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| Research Abstract |
In this project, we developed the Fourie-transform spectrophotometer equipped with the infrared microscope. The appratus enables measurement on single crystals of smaller size in a shorter time. We investigated the reflectance spectra of various organic high conductive radical salts and their electronic properties. Incorporating thecryostat, it is possible to measure the reflectance spectra at low temperatures. The characteristics of the appratus are as follows; (1) Alternative measurements between the sample and the reference is possible. (2) The smallest sample size available for measurement is 100 mumx100 mum and the geometry near normal incidence is satisfied. (3) As a half-mirror is not used, the range of wave numbers to be measured can be enlarged by changing the beam splitter and the detectors. (4) S/N ratio is high. (5) Maximum resolution is 0.5 cm^<-1> over the range of 4600-650 cm^<-1>.
The radical salts of DMET which is an asymmetrical donor are synthesized and their crystal
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structures and physical properties were investigated. The investigation of the temperature dependence of the electrical resistivities of DMET salts revealed that DMET salts can be classified into five groups. dmet salts with octahedral anions belong to group 1 and are semiconductor-like even at room temperature. DMET salts with tetrahedral anions belong to group 2 and exhibit a metal-semiconductor transition at around 40 K. The salts with some linear anions show metallic behavior down to low temperatures and turn to semiconductors and belong to group 3. The salts with some linear anions in group 4 show metal-lic behavior and do not show a resistance upturn even at ambient pressure. The salt with AuBr_2 anion show a resistance maxim and then metallic behavior and belongs to group 5. Au(CN)_2, Aul_2, AuCl_2, I_3, IBr_2 salts and two types of AuBr_2 salts were found to be superconductors. These are the fisrt organic superconductors based on an ansymmetrical donor. The reflectance spectra of these salts were measured and analysed. The relation between the spectra and the crystal structures are discussed. Less
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