Neutron scattering study of phonon-libron coupling in potassium-ammonia intercalated graphite.
Neutron scattering study of phonon-libron coupling in potassium-ammonia intercalated graphite.
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钾氨插层石墨中声子-利电子耦合的中子散射研究。
DOI：
10.1103/physrevb.37.8424
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发表时间：
1988
期刊：
影响因子：
--
通讯作者：
Rush
中科院分区：
文献类型：
--
作者：
Neumann;Zabel;Fan;Solin;Rush
本文介绍了k -氨插层石墨的[001]L晶格动力学的非弹性中子散射研究结果。结果表明，在7 meV左右的能量下，振动模式使第一阶段化合物的声声子分支分裂，不同通道的氨分子之间的相互作用非常弱。这种效应可以用一个简单的单力常数Born-von Kármán模型来描述，该模型将振动视为爱因斯坦振荡器，并且杂化遵循声子-libron耦合项。然而，这种附加模式的性质仍有待确定。此外，我们报告了K-氨体系中的弹性常数c33比类似的二元K化合物中的弹性常数c33要软得多。
We present the results of an inelastic neutron scattering study of the [001] L lattice dynamics of stage-1 and stage-2 K-ammonia intercalated graphite. The results show that a librational mode splits the acoustic-phonon branch of the stage-1 compound at an energy of about 7 meV and that the interaction between the ammonia molecules in different galleries is very weak. This effect can be described by a simple one-force-constant Born–von Kármán model with the libration treated as an Einstein oscillator and the hybridization follows from a phonon-libron coupling term. The nature of this additional mode, however, remains to be determined. In addition, we report that the elastic constant C 33 is considerably softer in the K-ammonia system than in the analogous binary K compounds.