Detection of the epsilon - delta phase transition in N2and a N2-He mixture by Raman spectroscopy: new evidence for the solubility of fluid He in solid N2
- 21 October 1991
- journal article
- Published by IOP Publishing in Journal of Physics: Condensed Matter
- Vol. 3 (42) , 8305-8312
- https://doi.org/10.1088/0953-8984/3/42/025
Abstract
The vibrons nu 1 and nu 2 of N2 have been measured around the epsilon - delta phase transition by Raman spectroscopy. Thus, for the first time the epsilon - delta transition could be detected in this way. The Raman shift of the nu 1-peak has been observed to be larger in the epsilon -phase than in the delta -phase and the Raman shift of the nu 2-peak smaller. More importantly, this feature has also been observed in the mixture N2-He with 9.2 mol.% He around the phase transition at p=60 kbar and T=245 K, which is new evidence for a considerable temperature and pressure shift of the epsilon - delta phase transition line in the mixture and also for the solubility of fluid He in solid epsilon -N2 at high pressures.Keywords
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