Raman spectroscopy and melting of nitrogen between 290 and 900 K and 2. 3 and 18 GPa
Raman spectroscopy was used to study the melting of nitrogen from 290 to 900 K at pressures from 2.3 to 18 GPa. This work, which extends the melting by a factor of 9 over previously published results was made possible by new developments in high-temperature diamond-anvil cells. The ..beta../delta phase boundary was also determined, and the ..beta..--delta--fluid triple point was found to be at 578 +- 10 K and 9.9 +- 0.5 GPa. The Raman frequencies of the vibron in fluid N/sub 2/ and the ..nu../sub 2/ vibron in delta-N/sub 2/ were found to have the same pressure dependence and be independent of temperature to a good approximation. A temperature-independent pressure scale, useful to at least 900 K is approximated by P/GPa = 0.4242 ..nu../cm/sup -1/ -987.8, where ..nu.. is the frequency of either the ..nu../sub 2/ vibron in delta-N/sub 2/ or the vibron in fluid-N/sub 2/.
- Research Organization:
- Los Alamos National Laboratory, Los Alamos, New Mexico 87545
- DOE Contract Number:
- W-7405-ENG-36
- OSTI ID:
- 6511456
- Journal Information:
- J. Chem. Phys.; (United States), Vol. 87:2
- Country of Publication:
- United States
- Language:
- English
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