HOMOGENEOUS DISPERSION OF DIELECTRIC RESPONSES IN A SIMPLE GLASS

Non-exponential patterns are well known characteristics of relaxations in glassy systems; however, the origin of dispersion is a matter of d ebate in many cases. Dielectric relaxation and solvation dynamic data are compared along the lines of the mean spherical approximation theor y for discriminating between homogeneous and heterogeneous nature of d ispersion for a low molecular weight glass at 3 K above the glass tran sition temperature, T-G. From the theoretical point of view, the neces sary spatial component stems from the dependence of solvation dynamics on epsilon(omega, k), rather than the macroscopic limit epsilon(omega , k = 0). It is shown that the two origins of dispersion can be distig uished in terms of solvation data which agree with the homogeneous lim it.