Open AccessЭффекты, связанные с ограниченной геометрией, в нанокомпозитах на основе мезопористых матриц 2D-SBA-15 и 3D-SBA-15, содержащих наночастицы нитрита натрия
Author(s) -
А. А. Набережнов,
Е. В. Стукова,
О. А. Алексеева,
С.А. Новикова,
Alexandra Franz
Publication year - 2019
Publication title -
žurnal tehničeskoj fiziki
Language(s) - English
Resource type - Journals
eISSN - 1726-748X
pISSN - 0044-4642
DOI - 10.21883/jtf.2019.12.48497.207-19
Subject(s) - materials science , ferroelectricity , nanocomposite , phase transition , phase (matter) , hysteresis , mesoporous material , transition temperature , dielectric , neutron diffraction , diffraction , analytical chemistry (journal) , composite material , thermodynamics , condensed matter physics , chemistry , organic chemistry , optics , physics , superconductivity , optoelectronics , catalysis
The temperature dependences of the ferroelectric order parameter for nanostructured sodium nitrite on heating and cooling have been obtained from the analysis of the temperature evolution of diffraction spectra of neutron scattering on nanocomposites, produced by embedding of sodium nitrite into the pores of the mesoporous matrices 2D-SBA-15 (average pore diameter 69 (4) Å) and 3D-SBA-15 (average pore diameter 94 (5) Å ). It is shown that on heating the phase transition from the ferroelectric phase to the paraelectric one occurs at TC = 433 ± 1 K for both nanocomposite materials. The sizes of nanoparticles in both nanocomposites are determined and it is established that their size decreases on heating at approaching to the ferroelectric phase transition temperature. Temperature hysteresis (~ 15–20 K) have been found in the temperature dependence of the order parameter between heating and cooling regimes.