1992 Fiscal Year Final Research Report Summary
The Study of Intercalation Field through Positron Injection and the Synthesis, Structures and Properties of Intercalation Compounds
| Project/Area Number |
03640414
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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 |
物理化学一般
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| Research Institution | International Christian University |
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Principal Investigator |
SANO Mizuka International Christian University. College of Liberal Arts, Professor, 教養学部, 教授 (20017312)
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| Co-Investigator(Kenkyū-buntansha) |
MURAKAMI Hideoki Tokyo Gakugei University. Faculty of Education, Professor, 教育学部, 教授 (30011000)
YOSHIDA Nobuyuki International Christian University. College of Liberal Arts, Lecturer, 教養学部, 講師 (30095674)
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| Project Period (FY) |
1991 – 1992
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| Keywords | Positron Annihilation / Positron Lifetime / 2,3-dichloro-9,10-anthraquinone / MnPS_3 / Fullerene / Carbon seventy / Tetrathiafulvalene / Graphite Intercalation Compound |
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| Research Abstract |
1. Synthesized 2,3-dichloro-9,10-anthraquinone, highly purified by zone-melting, was grown by the Bridgman method to a single crystal in which the molecular planes were oriented nearly in parallel. Positrons injected into a crystal, 14 x 8 x 6 mm^3 in size, which contained ca. 7.4 x 10^5 Bq^<22>NaCl at the center, emitted 511 keV gammaray upon annihilation with electrons in the crystal. Positrons were found to decay with a single lifetime component of 310 ps and the Doppler-broadening width along gamma// a was narrower than that along gamma// b or c, which demonstrated that the region where electrons moved freely was wider along the molecular C_<2v> axis. 2. The electronic structures of tetrathiafulvalene and pyridine intercalated into MnPS_3 single crystals were studied : the former was found to be in the mixed-valence state between TTF^+ and TTF^0, and the latter to form hydrogen-bonded PyH^+-Py complexes solvated with neutral pyridine molecules. The pyridine species were oriented perpendicularly to P_2S_6^<4-> layers. 3. A ternary intercalation compound of CsC_8 with hydrogen could be prepared by the reaction between CsC_8 and active hydrogen atoms generated on a hot tungsten filament. Gettering rates of RbC_8, KC_8 and CsC_8 for hydrogen gas were found to be large in this sequence, while those for oxygen were all in the order of 10^<-1>s^<-1>. A graphite-bromine intercalation compound in a diamond anvil cell showed pressure-induced phase transitions at 0.3, 0.8 and 1.2 GPa, which were found to be accompanied with inclination-changes of bromine-bonding axis against graphite layers. 4. Vaccum-sublimed C_<60> and C_<70>, isolated by column chromatography with 5% benzene in hexane on alumina, gave the positron-electron annihilation lifetimes of 427 and 403 ps, respectively, while C_<60>I_<0.08> gave two components for the lifetime spectrum.
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