Rovibrational transitions and nuclear spin conversion of methane in parahydrogen crystals
Vernadsky National Library of Ukraine
Переглянути архів Інформація| Поле | Співвідношення | |
| Title |
Rovibrational transitions and nuclear spin conversion of methane in parahydrogen crystals
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| Creator |
Miki, Masaaki
Momose, Takamasa |
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| Subject |
Low-Temperature Physics and Chemistry in Cryomatrice
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| Description |
Solid parahydrogen is an excellent matrix for matrix-isolation spectroscopy because of its high spectral resolution. Here we describe the rovibrational structure and nuclear spin conversion of CH₄ embedded in parahydrogen crystals studied by infrared absorption spectroscopy. The vibration–rotation absorptions of CH₄ exhibit time-dependent intensity changes at 4.8 K. These changes are interpreted to be a result of the I=1→I=2 nuclear spin conversion that accompanies the J=1→J=0 rotational relaxation. The half-lifetime of the upper J=1 rotational state is unchanged by the addition of up to 2% orthohydrogen molecules but decreases with more than 10% orthohydrogen molecules. The increase of the decay rate at higher orthohydrogen concentration indicates that the magnetic field gradient across CH₄ due to the orthohydrogen molecules mixes the nuclear spin states, which accelerates the conversion.
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| Date |
2018-01-16T20:02:47Z
2018-01-16T20:02:47Z 2000 |
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| Type |
Article
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| Identifier |
Rovibrational transitions and nuclear spin conversion of methane in parahydrogen crystals / Masaaki Miki, Takamasa Momose // Физика низких температур. — 2000. — Т. 26, № 9-10. — С. 899-908. — Бібліогр.: 52 назв. — англ.
0132-6414 PACS: 33.20.Ea, 33.70.-w, 82.20.Rp http://dspace.nbuv.gov.ua/handle/123456789/129214 |
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| Language |
en
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| Relation |
Физика низких температур
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| Publisher |
Фізико-технічний інститут низьких температур ім. Б.І. Вєркіна НАН України
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