skip to main content
OSTI.GOV title logo U.S. Department of Energy
Office of Scientific and Technical Information

Title: Polymorphism of dense, hot oxygen

Abstract

The phase diagram and polymorphism of oxygen at high pressures and temperatures are of great interest to condensed matter and earth science. X-ray diffraction and Raman spectroscopy of oxygen using laser and resistively heated diamond anvil cells reveal that the molecular high-pressure phase {var_epsilon}-O{sub 2}, which consists of (O{sub 2}){sub 4} clusters, reversibly transforms in the pressure range of 44 to 90 GPa and temperatures near 1000 K to a new phase with higher symmetry. The data suggest that this new phase ({eta}') is isostructural to a phase {eta} reported previously at lower pressures and temperatures, but differs from it in the P-T range of stability and type of intermolecular association. The melting curve increases monotonically up to the maximum pressures studied (-60 GPa). The structure factor of the fluid measured as a function of pressure to 58 GPa shows continuous changes toward molecular dissociation.

Authors:
; ; ; ; ;  [1];  [2]
  1. (CIW)
  2. (
Publication Date:
Research Org.:
Argonne National Lab. (ANL), Argonne, IL (United States). Advanced Photon Source (APS)
Sponsoring Org.:
NSFDOE - BASIC ENERGY SCIENCESNNSAU.S. ARMY RESEARCH
OSTI Identifier:
1023688
Resource Type:
Journal Article
Journal Name:
J. Chem. Phys.
Additional Journal Information:
Journal Volume: 135; Journal Issue: (8) ; 2011; Journal ID: ISSN 0021-9606
Country of Publication:
United States
Language:
ENGLISH
Subject:
75 CONDENSED MATTER PHYSICS, SUPERCONDUCTIVITY AND SUPERFLUIDITY; DIAMONDS; DISSOCIATION; FLUIDS; MELTING; OXYGEN; PHASE DIAGRAMS; PHASE TRANSFORMATIONS; PRESSURE RANGE; PRESSURE RANGE GIGA PA; RAMAN SPECTROSCOPY; STABILITY; STRUCTURE FACTORS; SYMMETRY; TEMPERATURE DEPENDENCE; TEMPERATURE RANGE 0400-1000 K; X-RAY DIFFRACTION

Citation Formats

Goncharov, Alexander F., Subramanian, N., Ravindran, T.R., Somayazulu, Maddury, Prakapenka, Vitali B., Hemley, Russell J., and UC). Polymorphism of dense, hot oxygen. United States: N. p., 2011. Web. doi:10.1063/1.3626860.
Goncharov, Alexander F., Subramanian, N., Ravindran, T.R., Somayazulu, Maddury, Prakapenka, Vitali B., Hemley, Russell J., & UC). Polymorphism of dense, hot oxygen. United States. doi:10.1063/1.3626860.
Goncharov, Alexander F., Subramanian, N., Ravindran, T.R., Somayazulu, Maddury, Prakapenka, Vitali B., Hemley, Russell J., and UC). Tue . "Polymorphism of dense, hot oxygen". United States. doi:10.1063/1.3626860.
@article{osti_1023688,
title = {Polymorphism of dense, hot oxygen},
author = {Goncharov, Alexander F. and Subramanian, N. and Ravindran, T.R. and Somayazulu, Maddury and Prakapenka, Vitali B. and Hemley, Russell J. and UC)},
abstractNote = {The phase diagram and polymorphism of oxygen at high pressures and temperatures are of great interest to condensed matter and earth science. X-ray diffraction and Raman spectroscopy of oxygen using laser and resistively heated diamond anvil cells reveal that the molecular high-pressure phase {var_epsilon}-O{sub 2}, which consists of (O{sub 2}){sub 4} clusters, reversibly transforms in the pressure range of 44 to 90 GPa and temperatures near 1000 K to a new phase with higher symmetry. The data suggest that this new phase ({eta}') is isostructural to a phase {eta} reported previously at lower pressures and temperatures, but differs from it in the P-T range of stability and type of intermolecular association. The melting curve increases monotonically up to the maximum pressures studied (-60 GPa). The structure factor of the fluid measured as a function of pressure to 58 GPa shows continuous changes toward molecular dissociation.},
doi = {10.1063/1.3626860},
journal = {J. Chem. Phys.},
issn = {0021-9606},
number = (8) ; 2011,
volume = 135,
place = {United States},
year = {2011},
month = {9}
}