| Project/Area Number |
62840012
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| Research Category |
Grant-in-Aid for Developmental Scientific Research
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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 | Hokkaido University |
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Principal Investigator |
YOSHIDA Hiroshi Faculty of Engineering, Hokkaido University, 工学部, 教授 (20027410)
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| Co-Investigator(Kenkyū-buntansha) |
ICHIKAWA Tsuneki Faculty of Engineering, Hokkaido University, 工学部, 講師 (10001942)
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| Project Period (FY) |
1987 – 1988
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| Project Status |
Completed (Fiscal Year 1988)
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| Budget Amount *help |
¥7,900,000 (Direct Cost: ¥7,900,000)
Fiscal Year 1988: ¥1,500,000 (Direct Cost: ¥1,500,000)
Fiscal Year 1987: ¥6,400,000 (Direct Cost: ¥6,400,000)
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| Keywords | Electron spin echo / Resolution enhancement / ESR, Alkyl radical / Spectral diffusion / Relaxation / Paramagnetic relaxation / アルキルラジカル / ループギャップ共振器 |
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| Research Abstract |
The present study has proved that the high-resolution ESR spectra of paramagnetic species in solids can be obtained by measuring the intensity of their electron spin echo signal as a function of external magnetic field. The reason why the resolution-enhanced ESR spectra are obtained is as follows; The resonant magnetic field of para-magnetic species depends on the nuclear arrangement with respect to the external mag-netic field and the unpaired electrons on them, which causes the broadening of the ESR spectrum. Paramagnetic relaxation rate also depends on the arrangement. In an electron spin echo method the electron spins are first excited by a microwave pulse and the magnetically unrelaxed spins are detected after some waiting Time. therefore, the distribution of the arrangement for the detected species becomes sharper with increasing the waiting time, which causes the sharpening of the ESR spectrum.
An example of the resolution enhancement has been given for the alkyl radicals in alkane solids. The resolution enhancement has been proven to be caused mainly by the thermal motion of B protons abjacent to the unpaired electrons. A simple and inexpensive electron spin echo spectrometer for high-resolution solid-state ESR has been constructed by using a loop-gap resonator and a newly developed coupling device.
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