Specific Features of Light Scattering in Oxide Glasses in the Glass Transition Range

Non-equilibrium fluctuations as a plausible reason of the light scattered intensity peak in the glass transition region

“…The results obtained confirm with the assumption in [9,10] that the temperature gradient is one of the possible reason of the appearing of the scattered light intensity after a temperature jump in the glass transition region.…”

“…The first steps in this direction were carried out in [8][9][10][11], where the influence of the thermal prehistory on the scattered intensity after temperature jumps in the glass transition region of germanate, phosphate and silicate glasses was observed. It was found that the time dependence intensity after the temperature jump from low-temperature to larger value exhibited the universal character, which manifested itself as a peak.…”

“…It was shown in the phosphate glass [10] that an enhancement of the peak height was proportional to the square of the temperature difference, which it was determined by a magnitude of the temperature jump. Taking into account these features, it should be assumed that the appearance of the intensity peak may be associated with the rise of the temperature gradient across the sample at the initial moments after the temperature jump [9,10]. It may be that the arising of the temperature gradient is connected with the finite quantity of the structural relaxation time which exceeds the time required to reach the temperature inside the sample.…”

Memory effect in the glass transition region of silicate glass based on light scattering data

“…Recently it was found that after temperature jumps time dependence of the integral light scattered intensity demonstrated the universal character, which manifested itself as a maximum in the glass transition region [8][9][10][11][12]. It was shown at least for the oxide glass that the maximum height and its location were depended on the thermal prehistory of a glass.…”

“…A step on the way to the solution of this problem was made in the previous work [8][9][10], in which by means of method up-jumps from stabilization temperature T st to observation temperature T obs the influence of thermal history of the phosphate glass was studied. It was found that the dependences of the maximum height and its location from the stabilization time t st at T st followed the exponential equation.…”