Raman spectroscopy in hot compressed hydrogen and nitrogen - implications for the intramolecular potential

Journal Article · Mon Sep 19 04:00:00 EDT 2005 · Physical Review Letters

OSTI ID:950087

Goncharov, A F; Crowhurst, J C

Raman measurements of molecular hydrogen (H{sub 2} and D{sub 2}) and nitrogen (N{sub 2}) have been made under simultaneous conditions of high temperature and high static pressure. Measurements have been made on H{sub 2} and D{sub 2} to 50 GPa and 1600 K, and on N{sub 2} to 50 GPa and 2000 K. In all three materials the familiar molecular stretching mode (vibron) is accompanied in the high-temperature Raman spectra by one or more lower-frequency peaks due to transitions from excited vibrational states. We find that the frequency differences between these bands decreases with pressure, implying that the anharmonicity of the corresponding part of the intramolecular potential also decreases. This is accompanied by an increase in the measured linewidths of the bands that is consistent with a decrease of the depth of the potential and an approaching molecular dissociation.

• Research Organization: Lawrence Livermore National Laboratory (LLNL), Livermore, CA
• Sponsoring Organization: USDOE
• DOE Contract Number: W-7405-ENG-48
• OSTI ID: 950087
• Report Number(s): UCRL-JRNL-215679
• Journal Information: Physical Review Letters, Journal Name: Physical Review Letters Journal Issue: 5 Vol. 96; ISSN 0031-9007; ISSN PRLTAO
• Country of Publication: United States
• Language: English

Related Subjects

71 CLASSICAL AND QUANTUM MECHANICS
GENERAL PHYSICS
74 ATOMIC AND MOLECULAR PHYSICS
75 CONDENSED MATTER PHYSICS
SUPERCONDUCTIVITY AND SUPERFLUIDITY
DISSOCIATION
HYDROGEN
NITROGEN
RAMAN SPECTRA
RAMAN SPECTROSCOPY
VIBRATIONAL STATES