Local Structure of Supercritical Fluids Investigated by Translational, Rotational, and Vibrational Motions

Abstract

The increasing use of supercritical fluids in a wide range of practical applications has motivated a number of resent attempts to understand the fundamental aspects of fluid structure. In this article, recent advances in experimental studies on local structure of supercritical fluids are reviewed. Especially, the local structures probed by three spectroscopic methods, i.e. dynamic light scattering, terahertz absorption, and vibrational Raman spectroscopies, are reported. These experimental results and theoretical analysis allow us to understand the local structure from the point of view on molecular motion, i.e. translational diffusion, rotational, and vibrational motions, by changing continuously density from the gas-like to liquid-like conditions.