Sound velocity and refractive index of pure N2 fluid and of equimolar N2-CO2 fluid mixture up to 15 GPa

S Ninet; G Weck; A Dewaele; F Datchi; V M Giordano; P Loubeyre

doi:10.1063/5.0021678

Sound velocity and refractive index of pure N₂ fluid and of equimolar N₂-CO₂ fluid mixture up to 15 GPa

J Chem Phys. 2020 Sep 21;153(11):114503. doi: 10.1063/5.0021678.

Authors

S Ninet¹, G Weck², A Dewaele², F Datchi¹, V M Giordano³, P Loubeyre²

Affiliations

¹ Institut de Minéralogie, de Physique des Matériaux et de Cosmochimie (IMPMC), Sorbonne Université, CNRS UMR 7590, IRD UMR 206, MNHN, 4, Place Jussieu, Paris, France.
² CEA, DAM, DIF, F-91297 Arpajon, France.
³ Institut Lumière Matière, UMR 5306 Université Lyon 1-CNRS, F-69622 Villeurbanne Cedex, France.

PMID: 32962385
DOI: 10.1063/5.0021678

Abstract

The sound velocity and refractive index of pure N₂ and of the equimolar N₂-CO₂ mixture are measured up to 15 GPa and 700 K in a resistive heating diamond anvil cell. The refractive index vs pressure is obtained by an interferometric method. The adiabatic sound velocity is then determined from the measurement of the Brillouin frequency shift in the backscattering geometry and the refractive index data. No phase separation of the N₂-CO₂ fluid mixture is observed. The fluid mixture properties are discussed in terms of ideal mixing.