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 debate in many cases. Dielectric relaxation and solvation dynamic data are compared along the lines of the mean spherical approximation theory for discriminating between homogeneous and heterogeneous nature of dispersion for a low molecular weight glass at 3 K above the glass transition temperature, T_G. From the theoretical point of view, the necessary spatial component stems from the dependence of solvation dynamics on ε{lunate}(ω, κ), rather than the macroscopic limit ε{lunate}(ω, κ = 0). It is shown that the two origins of dispersion can be distinguished in terms of solvation data which agree with the homogeneous limit.