Intermolecular coupling and fluxional behavior of hydrogen in phase IV
Intermolecular coupling and fluxional behavior of hydrogen in phase IV
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DOI：
10.1073/pnas.1916385116
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发表时间：
2019-12-17
影响因子：
11.1
通讯作者：
Mao, Ho-Kwang
中科院分区：
文献类型：
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作者：
Goncharov, Alexander F.;Chuvashova, Irina;Mao, Ho-Kwang
我们在上海同步辐射装置(SSRF)的红外同步加速器上进行了295K至280 GPa氢的拉曼光谱和红外光谱测量。为了达到最高压力，氢气被装载到中心为30微米的环形金刚石顶锤中。通过红外和拉曼振子模的伴随测量，确定了分子间的耦合。在第四阶段，我们发现在细长分子的类石墨层(G层)中的分子间耦合比在类Br2的短分子层(B层)中要强得多，并且在G层中随着压力的增加比在B层中要快得多。这些非均相晶格动力学性质是高流动性氢相IV的独特特征。
We performed Raman and infrared (IR) spectroscopy measurements of hydrogen at 295 K up to 280 GPa at an IR synchrotron facility of the Shanghai Synchrotron Radiation Facility (SSRF). To reach the highest pressure, hydrogen was loaded into toroidal diamond anvils with 30-mu m central culet. The intermolecular coupling has been determined by concomitant measurements of the IR and Raman vibron modes. In phase IV, we find that the intermolecular coupling is much stronger in the graphenelike layer (G layer) of elongated molecules compared to the Br2-like layer (B layer) of shortened molecules and it increases with pressure much faster in the G layer compared to the B layer. These heterogeneous lattice dynamical properties are unique features of highly fluxional hydrogen phase IV.