Light scattering by boron oxide in the temperature range of 225–330°C

Abstract

It is found that the process of variation in the intensity of the polarized component of the light scattered by boron oxide in the temperature range of 250–290°C after cooling from temperatures of 330 and 450°C possesses the peculiarities similar to those found earlier for the step-by-step mode of cooling for temperatures higher than 295°C and is characterized by the formation of a minimum. It is also detected that at lower temperatures the minimum possesses an asymmetric shape. It is shown that the process of increasing the intensity in time is satisfactorily approximated by an empirical equation of an exponential form. It is found that the change in the relaxation times with the temperature corresponds to an exponential law for the entire set of the data that we have obtained. It is found that the change in the depolarized component intensity in the region of low temperatures is relatively small, which makes it possible to associate the behavior of the polarized component with the change in the value of isotropic scattering. It is shown that in agreement with the results obtained earlier the time dependence of the intensity of the polarized component at a higher temperature for a sample preliminarily annealed at a low temperature is characterized by the formation of a maximum. The experimental results that we have obtained indicate the universal character of the manifestation of a peculiarity in the behavior of the scattered light intensity in the process of cooling and heating of boron oxide in the glass transition range.