Coefficients du viriel de la réfractivité de l'azote a 25 °C

Abstract

We measured accurately the refractive index of nitrogen at 25 °C between 40 and 400 bar, and calculated the refractivity R = (n2 − 1)/(n2 + 2)1/ρ. Particular attention is given to the determination of the density ρ, which is the limitation of accuracy on R. We calculate the refractivity virial coefficients AR, BR, and CR, the last one being given for the first time.The results are compared with the published data, the dielectric virial coefficients, and the induced absorption. The Buckingham expression of BR is calculated for N2 and compared with our values.