Тип публикации: статья из журнала
Год издания: 2022
Идентификатор DOI: 10.1016/j.jnoncrysol.2022.121935
Ключевые слова: 62.23.pq, 64.70.nd, 65.80.-g, 77.80.-e, entropy, ferroelectrics, nanocomposite, phase transition, thermal expansion
Аннотация: The thermal properties of nanocomposites obtained by incorporating a ferroelectric (NH4)2SO4 (AS) into porous glasses (PG) was studied for the first time. X-ray diffraction studies showed a strong increase in the ratio of the size of nanocrystallites grown in glass matrices to pore size, dcryst/ dpore = 0.47→1.50→5.00, with a decreПоказать полностьюase in dpore = 320→46→7 nm. Calorimetric and dilatometric measurements showed a change from a first-order phase transition in AS single crystal to a second-order transformation in AS nanocrystallites. A restricted geometry also led to a significant decrease in the anomalous entropy in AS+PG samples compared to AS (J/mol∙K): 17.7 (AS)→12.4 (AS+PG320)→10.4 (AS+PG46)→8.1 (AS+PG7). A discussion of the nontrivial behavior of the phase transition temperature in embedded AS was carried out using the degree of PG filling, the ratio dcryst/dpore, texture, and the volumetric and linear baric coefficients for the bulk AS. © 2022
Журнал: Journal of Non-Crystalline Solids
Выпуск журнала: Vol. 597
Номера страниц: 121935
ISSN журнала: 00223093
Издатель: Elsevier B.V.