Spectroscopy of glassy systems with a relaxation-time distribution: Application to Brillouin scattering on Rb0.65(NH4)0.35H2PO4

Abstract

Glassy systems often have a broad distribution of relaxation times difficult to determine experimentally. A new approach for spectrum analysis, which could find considerable application, is described. It is based on the expansion of a relaxation function in the logarithm of the frequency, and applied successfully to Brillouin data on ${\mathrm{Rb}}_{0.65}$(${\mathrm{NH}}_4$ ${)}_{0.35}$ ${\mathrm{H}}_2$ ${\mathrm{PO}}_4$ demonstrating the physical interpretation of the experimental expansion coefficients.