Two-phonon Raman scattering of light in argon at high temperatures

The two-phonon Raman spectra of solid argon at 60 K, 22.1 cm³/mole and at 153.5 K, 22.3 cm³/mole are calculated, with phonon frequencies obtained from a calculation in which cubic anharmonicity is included self-consistently and short-range correlations are incorporated. The results are compared with existing molecular dynamics calculations and with experimental measurements. Certain general trends, such as the presence of a two-phonon cutoff and a smoothing out of the features of the spectra, are correctly reproduced, but the calculations predict too low intensity at frequencies around 40 cm^–1, between the sum and difference bands.Supported in part by a grant from the Rutgers University Research Council.Work submitted in partial fulfillment of the requirements of the Ph.D. degree at Rutgers University.