Nabereznov, A. A.; Stukova, E. V.; Alekseieva, O. A.; Novikova, S. A.; Franz, A.: Effecty, sviazannye s ogranichennoi geometriei, v nanokompozitah na osnove mezoporistyh matrits 2D-SBA-15 i 3D-SBA-15, soderzhashhih nanochastitsy nitrita natria. Žurnal Techniceskoj fiziki = Journal of Applied Physics 89 (2019), p. 1965-1970
10.21883/JTF.2019.12.48497.207-19
Open Access Version
Abstract:
Temperature dependences of the ferroelectric order parameter for nanostructured sodium nitrite under heating and cooling were obtained by analyzing the temperature evolution of diffraction spectra of neutron scattering by composites obtained by introducing sodium nitrite into pores of mesoporous 2D-SBA-15 (the average pore diameter is 69(4) Å) and 3D-SBA-15 (94(5) Å) matrices. It was demonstrated that the phase transition to the paraelectric phase in the process of heating occurs at TC = 433 ± 1 K in both nanocomposite materials. It was found that these sizes decrease at approaching to the ferroelectric phase transition point on heating. Temperature hysteresis (~15–20 K) in the temperature dependence of the order parameter between the heating and cooling regimes was revealed.