Quantum rotations in natural methane-clathrates from the Pacific seafloor
Quantum rotations in natural methane-clathrates from the Pacific seafloor
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DOI：
10.1209/epl/i1999-00476-x
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发表时间：
1999-11-01
期刊：
影响因子：
--
通讯作者：
Hüller, A
中科院分区：
文献类型：
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作者：
Gutt, C;Asmussen, B;Hüller, A
本文报道了索内号考察船考察期间从太平洋海底采集的天然甲烷水合物的非弹性中子散射实验。实验通过测量甲烷分子的转动光谱直接验证了甲烷的含量。几乎自由转动能级的存在排除了笼中分子的偏心位置。此外，我们可以分配观察到的峰值在能量制度高达5毫电子伏的旋转激发。所观察到的相对尖锐的激发证明了地质样品的令人惊讶的良好结晶度。有限的宽度归因于冰笼的冻结氢无序。
We report inelastic neutron scattering experiments from natural methane hydrates sampled from the Pacific sea-floor during an expedition of the research ship SONNE. The experiments verify directly the content of methane by measuring the rotational spectrum of the CH4 molecules. The existence of almost free rotational levels excludes off-center positions of the molecules in the cages. In addition we could assign the observed peaks in the energy regime up to 5 meV to rotational excitations only. The observed relative sharp excitations prove a surprisingly good crystallinity of the geological sample. The finite width is attributed to frozen-in hydrogen disorder of the ice cages.