X-ray diffraction studies and equation of state of methane at 202 GPa

Journal Article · Wed Apr 22 00:00:00 EDT 2009 · Chem. Phys. Lett.

DOI:https://doi.org/10.1016/j.cplett.2009.03.072· OSTI ID:1005575

Sun, Liling; Yi, Wei; Wang, Lin; Shu, Jinfu; Sinogeikin, Stas; Meng, Yue; Shen, Guoyin; Bai, Ligang; Li, Yanchuan; Liu, Jing; Mao, Ho-kwang; Mao, Wendy L

Solid methane (CH{sub 4}) was compressed up to 202 GPa at 300 K in a diamond-anvil cell. The crystal structure and equation of state over this entire range were determined from angle dispersive X-ray diffraction results. CH{sub 4} undergoes phase transitions from rhombohedral to a simple cubic phase at 19 GPa and from simple cubic to a higher pressure cubic phase at approximately 94 GPa. This higher pressure cubic phase was stable to the maximum pressure investigated. Combined with previous optical measurements, it was found that at room temperature compressed CH{sub 4} remains an insulator with cubic structure to 202 GPa.

• Research Organization: Argonne National Lab. (ANL), Argonne, IL (United States)
• Sponsoring Organization: USDOE
• OSTI ID: 1005575
• Journal Information: Chem. Phys. Lett., Vol. 473, Issue (1-3) ; 04, 2009; ISSN 0009-2614
• Country of Publication: United States
• Language: ENGLISH

Related Subjects

03 NATURAL GAS
36 MATERIALS SCIENCE
AMBIENT TEMPERATURE
CRYSTAL STRUCTURE
EQUATIONS
EQUATIONS OF STATE
METHANE
PHASE TRANSFORMATIONS
PRESSURE RANGE GIGA PA
RANGE
SOLIDS
TEMPERATURE RANGE 0273-0400 K
X-RAY DIFFRACTION