Exploring High-Pressure Transformations in Low-Z (H2, Ne) Hydrates at Low Temperatures
Author:
Brant Carvalho Paulo H. B.,
Mace Amber,
Nangoi Inna MarthaORCID,
Leitão Alexandre A.,
Tulk Chris A.,
Molaison Jamie J.ORCID,
Andersson OveORCID,
Lyubartsev Alexander P.,
Häussermann UlrichORCID
Abstract
The high pressure structural behavior of H2 and Ne clathrate hydrates with approximate composition H2/Ne·~4H2O and featuring cubic structure II (CS-II) was investigated by neutron powder diffraction using the deuterated analogues at ~95 K. CS-II hydrogen hydrate transforms gradually to isocompositional C1 phase (filled ice II) at around 1.1 GPa but may be metastably retained up to 2.2 GPa. Above 3 GPa a gradual decomposition into C2 phase (H2·H2O, filled ice Ic) and ice VIII’ takes place. Upon heating to 200 K the CS-II to C1 transition completes instantly whereas C1 decomposition appears sluggish also at 200 K. C1 was observed metastably up to 8 GPa. At 95 K C1 and C2 hydrogen hydrate can be retained below 1 GPa and yield ice II and ice Ic, respectively, upon complete release of pressure. In contrast, CS-II neon hydrate undergoes pressure-induced amorphization at 1.9 GPa, thus following the general trend for noble gas clathrate hydrates. Upon heating to 200 K amorphous Ne hydrate crystallizes as a mixture of previously unreported C2 hydrate and ice VIII’.
Funder
Swedish National Infrastructure for Computing
Swedish Foundation for International Cooperation in Research and Higher Education
Coordenação de Aperfeicoamento de Pessoal de Nível Superior
Subject
Inorganic Chemistry,Condensed Matter Physics,General Materials Science,General Chemical Engineering
Cited by
2 articles.
订阅此论文施引文献
订阅此论文施引文献,注册后可以免费订阅5篇论文的施引文献,订阅后可以查看论文全部施引文献