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Abstract
The autocorrelation function of small amplitude capillary ripples was studied as a function of temperature for para-azoxyanisole (PAA). Measurements were carried out in the temperature range of 125°-148°C with the transition temperature observed to be 135°C. We will report our results for the case of q = 252.0 cm−1. The spectra of the autocorrelation functions were fit by Lorentzian models to yield the surface tension as a function of temperature. Several “temperature jump” measurements were made wherein the current to the heaters was changed so that the equilibrium temperature at T 0 was perturbed slightly. Correlation functions were determined as the temperature increased to a new equilibrium state. Large shifts in frequency and time damping of the autocorrelation function were observed only when the temperature jump spanned the nematic-isotropic transition temperature. These results will be discussed. Equilibrium surface tension numbers are reported. The theory and practice for the light scattering measurement will be outlined briefly.