The distribution of relaxation frequencies from photon correlation spectroscopy near the glass transition.
01 January 1985
The relaxation function obtained by photon correlation spectroscopy of a liquid near the glass transition has a highly nonexponential decay. This nonexponential behavior can be represented by a distribution of exponential relaxation processes. Using a real-time, 4-bit, 4-sample time, 256-channel correlator we have obtained very high quality depolarized spectra of polystyrene over seven decades in time. The relaxation function was calculated from the data and a least squares fit to the weighing factors of a sum of exponentials was performed using techniques described by Ostrowsky.