The effect of oxygen vacancies on the optical and thermophysical properties of (1-x)Si3N4 – xAl2O3 ceramics
Borgekov D.B. Zhumazhanova A.T. Kaliyekperova K.B. Azambayev S.B. Kozlovskiy A.L. Konuhova M. Popov A.I. Shlimas D.I.
November 2024Elsevier B.V.
Optical Materials
2024#157
Interest in composite ceramics based on silicon nitride (Si3N4) and aluminum oxide (Al2O3) is due to the possibility of using them as semiconductor applications associated with their operation under conditions of external influences, including heating. The paper presents the results of assessing the influence of variations in the phase composition of (1-x)Si3N4 – xAl2O3 ceramics on alterations in optical and thermophysical parameters, as well as their relationships. Analysis of the optical characteristics of the ceramics under study showed that changes in the phase composition associated with the dominance of the Al2O3 phase in the composition of the ceramics lead to a change in covalent bonds and an increase in the number of ionic bonds, which also affects the change in the semiconductor nature of the ceramics, and therefore, a change in the thermophysical properties. According to the assessment of changes in the thermal conductivity coefficient of the studied ceramics, with the dominance of the Al2O3 phase in the composition, the observed growth in the concentration of structural defects, as well as oxygen vacancies, results in the thermal conductivity coefficient decrease, as well as an elevation in the thermal expansion of ceramics during thermal heating. It has been determined that the presence of a combination of Al2(SiO4)O and Si3N4 phases in the ceramic composition leads to an increase in the thermal conductivity coefficient, as well as maintaining its stability over a wide temperature range.
Composite ceramics , Oxygen vacancies , Phase transformations , Thermal conductivity , Vacancy defects
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Engineering Profile Laboratory, L.N. Gumilyov Eurasian National University, Astana, 010008, Kazakhstan
Laboratory of Solid State Physics, The Institute of Nuclear Physics, Almaty, 050032, Kazakhstan
Institute of Solid State Physics University of Latvia, 8 Kengaraga str, Riga, LV-1063, Latvia
Engineering Profile Laboratory
Laboratory of Solid State Physics
Institute of Solid State Physics University of Latvia
10 лет помогаем публиковать статьи Международный издатель
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