Raman scattering from condensed argon

Two-phonon Raman spectra have been measured for solid-argon samples at two densities at low temperature. These results are compared with published calculations based on a point-dipole model, and some shortcomings of this model are indicated. The development of the Raman spectra with increasing temperature in the solid at constant density has been studied, and the results discussed in the context of this model. Finally, spectra were measured for solid and fluid argon at a number of points along the melting curve at pressures up to 4 kbar, in order to explore the changes which occur upon melting. These results are compared with previously published data for fluid argon at other temperatures and pressures. Some comparisons with molecular-dynamics calculations are also made.