Lithium polyhydrides synthesized under high pressure and high temperature
Lithium polyhydrides synthesized under high pressure and high temperature
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高压高温合成多氢化锂
DOI：
10.1002/jrs.5183
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发表时间：
2017
影响因子：
2.5
通讯作者：
Sasaki Shigeo
中科院分区：
文献类型：
--
作者：
Matsuoka Takahiro;Kuno Keiji;Ohta Kenji;Sakata Masafumi;Nakamoto Yuki;Hirao Naohisa;Ohishi Yasuo;Shimizu Katsuya;Kume Tetsuji;Sasaki Shigeo
高压下的碱金属多金属化合物由于具有超导电性和超压稳定的非传统化学计量比而引起了人们的极大兴趣。我们已经进行了拉曼散射测量的锂聚合物在高压和高温条件下合成高达182 GPa。在30~180 GPa之间，共出现4个相，暂命名为α（30-140 GPa）、β（30-90 GPa）、γ（90-140 GPa）和δ（140 GPa）相。通过观察H2振动子的波数及其与压力的关系，发现α相的晶格中含有电中性的H2，没有Li原子的电子转移.与含H2的稀有气体化合物Ar（H2）2、Kr（H2）4和Kr（H2）8的比较表明，在α相中，一个H2分子被六到八个相邻的H2分子包围。另一方面，β、γ和δ相的拉曼光谱表明，它们含有被从周围基质转移的电子带负电的拉长的H2。所有的α，β，γ和δ相被发现在低于182 GPa的压力下保持透明绝缘体。版权所有© 2017约翰威利父子有限公司
Polyhydrides of alkali metals under high pressures have been attracting great interests owing to the predicted pressure‐stabilized untraditional stoichiometries and potential superconductivity. We have performed Raman scattering measurements of lithium polyhydrides synthesized under high pressure and high temperature conditions up to 182 GPa. Between 30 and 180 GPa, four phases appear, and they are tentatively namedα(30–140 GPa),β(30–90 GPa),γ(90–140 GPa), andδ(140 GPa) phase. By observing the H2vibrons at higher wavenumbers than pure H2and their pressure dependence, it was revealed that theαphase contains electrically neutral H2in its crystal lattice without electron transfer from Li atoms. The comparisons with H2‐containing rare gas compounds Ar(H2)2, Kr(H2)4, and Xe(H2)8suggest that a H2molecule is surrounded by six to eight neighboring H2molecules in theαphase. On the other hand, the Raman spectra of theβ,γ, andδphases suggest that they contain the elongated H2that is negatively charged by the electron transferred from the surrounding matrices. All theα,β,γ, andδphases were found to remain transparent insulators at pressures below 182 GPa. Copyright © 2017 John Wiley & Sons, Ltd.