Guest disorder and high pressure behavior of argon hydrates

Journal Article · Mon Mar 29 00:00:00 EDT 2010 · Chem. Phys. Lett.

DOI:https://doi.org/10.1016/j.cplett.2009.12.024· OSTI ID:1002309

Yang, L; Tulk, C A; Klug, D D; Chakoumakos, B C; Ehm, L; Molaison, J J; Parise, J B; Simonson, J M ^[1]

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1. NRCC

The structure of argon hydrate was studied at ambient pressure and low temperature, and between 1.7 and 4.2 GPa at 295 K. This analysis produced a single Ar guest atom, positionally disordered off-center in the large cages of sII. Above 1.7 GPa Ar clathrate transformed to a mixture of a body-centered orthorhombic filled-ice phase, which can be viewed as a polytype of ice-Ih, and high pressure forms of pure ice. The guest disorder is further substantiated by analysis of the guest to host ratio in this high pressure filled-ice structure. The bulk modulus of Ar filled-ice found to be 11.7 {+-} 0.4 GPa.

• Research Organization: Advanced Photon Source (APS), Argonne National Laboratory (ANL), Argonne, IL (US)
• Sponsoring Organization: USDOE
• OSTI ID: 1002309
• Journal Information: Chem. Phys. Lett., Journal Name: Chem. Phys. Lett. Journal Issue: (1-3) ; 01, 2010 Vol. 485; ISSN CHPLBC; ISSN 0009-2614
• Country of Publication: United States
• Language: ENGLISH

Related Subjects

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CHEMISTRY
ARGON COMPOUNDS
HYDRATES
ICE
ORDER PARAMETERS
PHASE TRANSFORMATIONS
PRESSURE RANGE GIGA PA