Structural and spectroscopic studies of nitrogen-carbon monoxide mixtures: Photochemical response and observation of a novel phase
Abstract
Mixtures of nitrogen and carbon monoxide in two molar compositions (90-10 and 95-5 N2—CO) have been studied with Raman spectroscopy, X-ray diffraction, and first-principles density functional theory. Near 16 GPa, there is a discontinuous change in the X-ray diffraction patterns indicating a transition to phase I, which is distinct from any known phase of nitrogen. With the help of theory, the X-ray diffraction pattern was indexed to a triclinic unit cell. The evolutionary crystal structure search also identified several metastable stoichiometries of C—O—N phases, which produce distinct signatures in the experimental Raman spectra, thus explaining anomalous Raman behavior. Decompression studies showed that phase I did not persist below the melt line of nitrogen and, as such, it can be concluded that all observations are reversible.
Document Details
- Document Type
- Pub Defense Publication
- Publication Date
- May 12, 2017
- Source ID
- 10.1063/1.4983040
Entities
People
- Brad A Steele
- Gustav M Borstad
- Ivan I Oleynik
- Jennifer A Ciezak-Jenkins
Organizations
- Army Research Office
- Defense Threat Reduction Agency
- National Science Foundation
- Oak Ridge Associated Universities
- United States Army Research Laboratory
- United States Department of Energy
- University of South Florida