Light scattering studies of a glass forming liquid near T _g

Abstract

The cluster growth dynamics and the equilibrium cluster correlation length were studied in 1,1-di(4′-methoxy-5′-methyl-phenyl)-cyclohexane (BMMPC also called BKDE in previous papers) in the temperature range from 40°C to 70°C by means of static light scattering (SLS) and photon correlation spectroscopy (PCS). The equilibrium cluster correlation length obtained from PCS and SLS using the Ornstein Zernike formula are in a good agreement with each other. The analysis of the SLS data based on the Debye formula results in much lower values of the cluster correlation length. The relaxation processes in BMMPC were studied using depolarized Rayleigh spectroscopy (DRS). The relaxation times obtained from DRS exhibit an Arrhenius behaviour and with decreasing temperature diverge from the relaxation times of the primary α process measured by means of dielectric spectroscopy which follow the usual Williams-Landel-Ferry temperature dependence.