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The time dependence of the integral intensity of scattered light observed after temperature jumps in single-phase oxide glasses in the glass transition range exhibits a universal character, which manifests itself as a maximum [1][2][3]. The height of the maximum was shown to depend on the temperature jump magnitude and the size of the sample under consideration. Taking into account the specific features found, this effect can be associated with a temperature gradient across the sample after the temperature jump. A possible reason for the appearance of this gradient can be the finite structural relaxation time, which exceeds the time it takes for the temperature near the sample surface to be established. This fact accounts for the appearance of a difference in temperature between the central part of the sample and its surface at early stages after the temperature jump.Theoretical analysis of light scattering by liquids subjected to a constant temperature gradient shows that the interaction of hydrodynamic modes (which is absent in the equilibrium state) changes the scattered light spectrum and increases the integral intensity of the scattered light [4][5][6]. Theoretically, the nonequilibrium component of the integral intensity should be proportional to the square of the temperature gradient ( ∇ T ) 2 . Experimental findings for liquids support the theoretical conclusions [7,8].The objective of the present work was to study the effect of the temperature gradient on the intensity maximum in the glass transition range of two oxide glasses of different chemical nature and compare the results obtained with the theoretical predictions for light scattering by nonequilibrium liquids [4][5][6].The objects of this study were phosphate and silicate glasses, designated as nos. 1 and 2, respectively. Glass no. 1 was obtained under laboratory conditions. According to chemical analysis, it contained 9.4 mol % Na 2 O , 57.7 mol % ZnO, and 32.9 mol % P 2 O 5 . Commercially available silicate glass no. 2 contained silicon, boron, and barium oxides as major components and aluminum, zinc, and lanthanum oxides as additions. The glass transition temperatures T g of glasses nos. 1 and 2 were 370 and 640°ë , respectively. The behavior of the scattered light intensity was studied by the temperature jump method, which was described in detail in [2, 3]. The measured characteristic was the magnitude of the polarized component V v (90°) of the scattered light corresponding to the wavelength λ = 4880 Å of the incident laser radiation.Two procedures were used for measuring the temperature gradient. In the first series of runs, the gradient was specified by the temperature jump, and in the second series, by the size of the samples to be studied. The temperature jump was changed by changing the preliminary stabilization temperature T st from which the temperature jump was performed. The temperature T o at which the maximum was observed was constant. The samples of the first series had constant size, 12 × 15 × 31 mm (glass no. 1) and 12 × 15 × 18...

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