Piezo- and elasto-optic properties of liquids under high pressure. II. Refractive index vs density

Abstract

In Paper I of this series it was shown that high pressure interferometric measurements on a number of liquids reveal that the refractive index of liquids increases linearly with Eulerian strain even though the volume strain involved is as high as 33%. Further, it was also found that this linearity criterion can be used to discriminate between the various equations of state for liquids and that Keane's equation appears to be universally valid for all liquids. Having thus established the P-V relationship of liquids, the next problem of the refractive index-density relationship of liquids is considered in this article, The various equations prevalent in the literature--namely, Lorentz-Lorenz, Drude, Eykman, Onsager-Bottcher, Kirkwood-Brown, and Omini equations-are analyzed. The last two equations have been derived using a detailed statistical mechanical approach. It is found that none of these equations can predict the elastooptic behavior of liquids at high pressure quantitatively even though the latter two equations appear to yield values in reasonably good agreement with experimentally observed values.

Correlations between SARA Fractions, Density, and RI to Investigate the Stability of Asphaltene

“…The refractive index is expressed as a function of composition and density through the Clausius-Mossotti or Lorenz-Lorentz equation [43,44] in which the validity of the Lorenz-Lorentz equation to describe the density dependence of RI was investigated by Vedam and Limsuwan [44].…”

Study of the Influence of Temperature on the Deposition of SiO₂ Films from Reaction of Silicone Oil Vapor and Ozone Gas

“…As a result decrease in density as porosity is increased in the structure. Now, from the Lorentz-Lorentz model [44][45][46][47], there is a physical relation between density and refractive index (the refractive index is directly proportional to the density of the film), So that, refractive index is inversely proportional to the Si-OH(2) bond.…”

Application of spectroscopic ellipsometry for investigations of compaction and decompaction state in Si-SiO2systems

“…Other formulas relating oxide density and its refractive index are: Gladstone-Dale equation [10,11] (G-D):…”

“…Next, the density of SiO 2 layers obtained in this way were compared with that determined from the value of the refractive index (established in the course of ellipsometric measurements). The LorentzLorenz formula [8][9][10] (L-L) is one of the common used equation relating oxide density to its refractive index:…”