New phases and chemical reactions in solid CO under pressure. [15 to 300/sup 0/K, 1. 0 to 10. 0 GPa]

Conference · Sun Jan 01 04:00:00 EST 1984

OSTI ID:6509982

Mills, R L; Schiferl, D; Katz, A I; Olinger, B W

The phase diagram of solid carbon monoxide was determined by x-ray diffraction and Raman spectroscopy from 15 to 297 K at pressures from 1.0 to 10.0 GPa. At low temperature a transition occurs near 3.4 GPa from the known ..cap alpha..-phase (space group P2/sub 1/3) to a new epsilon-phase (structure unknown), rather than to the predicted ..gamma..-phase (P4/sub 2//mnm). A transformation from ..beta..-CO (space group P6/sub 3//mmc) into a new delta-phase (Pm3n) was found near 5.2 GPa at room temperature. Above about 4.6 GPa and 80 K, CO reacts photochemically when irradiated with visible laser light. The photoreactivity may be associated with the formation of a yellow polymer, which can be recovered at zero pressure. ESCA measurements indicate that the polymer is composed of carbon suboxide (C/sub 3/O/sub 2/)/sub x/. 19 references.

• Research Organization: Los Alamos National Lab., NM (USA)
• DOE Contract Number: W-7405-ENG-36
• OSTI ID: 6509982
• Report Number(s): LA-UR-84-2994; CONF-8409145-1; ON: DE85002033
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
360602* -- Other Materials-- Structure & Phase Studies
CARBON COMPOUNDS
CARBON MONOXIDE
CARBON OXIDES
CHALCOGENIDES
COHERENT SCATTERING
DATA
DIAGRAMS
DIFFRACTION
EXPERIMENTAL DATA
INFORMATION
LASER SPECTROSCOPY
LOW TEMPERATURE
NUMERICAL DATA
OXIDES
OXYGEN COMPOUNDS
PHASE DIAGRAMS
RAMAN SPECTROSCOPY
SCATTERING
SPECTROSCOPY
VERY HIGH PRESSURE
VERY LOW TEMPERATURE
X-RAY DIFFRACTION