Influence of synthesis conditions on the crystal structure of the powder formed in the ZrO2 - Ce2O3/CeO2 system.

Influence of synthesis conditions (type of atmosphere, reduction and oxidation, annealing temperature) on the chemical composition and structure of the compounds formed in the "ZrO2 - Ce2O3 / CeO2" system has been investigated by X-ray absorption fine structure (XAFS) spectroscopy combined with X-ray diffraction (XRD) and thermogravimetric analysis (TGA). It is revealed that isothermal annealing of precursor at temperatures less than 1000 °C in air leads to formation of Ce0.5Zr0.5O2 powders with cubic fluorite-type structure (Fm-3m). Further increase of annealing temperatures above 1000 °C causes decomposition of formed crystal structure into two phases: cubic and tetragonal. Annealing in reduction hydrogen atmosphere causes formation of Ce4 + 2xCe3 + 2-2xZr2O7 + x compounds with intermediate valency of cerium, where value of x depends on the reducing conditions and treatment parameters of precursor. Annealing in vacuum at 1400 °C strongly reduces the content of Ce4+ in a powder samples and leads to formation of pyrochlore structure (space group Fd-3m) with practically Ce3+ valence state.

Авторы
Popov V.V.1, 2 , Menushenkov A.P.1 , Khubbutdinov R.M.1 , Svetogorov R.D.2 , Zubavichus Y.V.2 , Sharapov A.S.1 , Kurilkin V.V. 3
Сборник материалов конференции
Издательство
Institute of Physics Publishing
Номер выпуска
1
Язык
Английский
Статус
Опубликовано
Номер
012041
Том
747
Год
2016
Организации
  • 1 National Research Nuclear University MEPhI, Moscow Engineering Physics Institute, Kashirskoe sh. 31, Moscow, 115409, Russian Federation
  • 2 NRC, Kurchatov Institute, pl. Akademika Kurchatova 1, Moscow, 123182, Russian Federation
  • 3 Peoples' Friendship University of Russia, Russian Federation
Ключевые слова
Annealing; Atmospheric temperature; Cerium; Cerium compounds; Chemical analysis; Chemical compounds; Isothermal annealing; Thermogravimetric analysis; X ray absorption; X ray diffraction; Zirconium alloys; Annealing in vacuum; Annealing temperatures; Chemical compositions; Hydrogen atmosphere; Pyrochlore structures; Reducing conditions; Synthesis conditions; Treatment parameters; Crystal structure
Дата создания
19.10.2018
Дата изменения
19.10.2018
Постоянная ссылка
https://repository.rudn.ru/ru/records/article/record/3809/
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