O2 / N2 mixtures under pressure: A structural study of the binary phase diagram at 295 K
Abstract
The binary phase diagram of O2/N2 mixtures has been measured at 295K up to 14GPa in a diamond anvil cell. The boundary lines and the structures of the various solid phases have been determined by the combination of visual observation of the phase transitions, synchrotron x-ray diffraction, and Raman spectroscopy. A large substitution of O2 , up to 20%, in solid N2 does not modify the sequence of structures observed in pure N2 solid. On the other hand, only less than 5% of N2 can be substituted in solid O2 . Five structures of O2/N2 solid solutions have been identified. In particular, a continuous solid solution obtained by substitution of O2 molecules in the δ-N2 phase is observed to extend up to 95mol% O2 . Deviation from pure random substitution is observed. Also, evidence of the existence of two compounds, (N2)3O2 and N2(O2)2 , are discussed.
- Publication:
-
Physical Review B
- Pub Date:
- October 2004
- DOI:
- Bibcode:
- 2004PhRvB..70m4105S
- Keywords:
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- 62.50.+p;
- 64.75.+g;
- 78.70.Ck;
- 78.30.-j;
- High-pressure and shock wave effects in solids and liquids;
- Solubility segregation and mixing;
- phase separation;
- X-ray scattering;
- Infrared and Raman spectra