Polarizability α (ω, T, ρ) of Small Molecules in the Gas Phase

The dependence of the mean dipole polarizability α(ω,T, ρ) of small molecules in the gas phase on electromagnetic radiation frequency ω, temperature T, and molar density ρ is discussed. Experimental results are presented for the noble gases, the molecular gases H2, N2, O2, CO2, CH4, C(CH3)4, CH3OH, CF2Cl2, and the gas mixture air. Hints to some rather unusual effects concerning α(ω,T, ρ) are given, too. In each case α(ω,T, ρ) was derived from precise interferometric measurements of the refractive index n(ω,T, ρ) of the gas in the visible (VIS) frequency range.