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Synthesis and Direct Sintering of Nanosized (M IV ,M III )O 2‐ x Hydrated Oxides as Electrolyte Ceramics
Author(s) -
Clavier Nicolas,
Cherkaski Yanis,
Martinez Julien,
Costis Sophie,
Cordara Théo,
Audubert Fabienne,
Brissonneau Laurent,
Dacheux Nicolas
Publication year - 2017
Publication title -
chemphyschem
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.016
H-Index - 140
eISSN - 1439-7641
pISSN - 1439-4235
DOI - 10.1002/cphc.201700647
Subject(s) - microstructure , sintering , materials science , ceramic , electrolyte , precipitation , hydroxide , pellets , chemical engineering , reactivity (psychology) , mineralogy , nuclear chemistry , metallurgy , inorganic chemistry , chemistry , composite material , medicine , physics , alternative medicine , electrode , pathology , meteorology , engineering
Highly reactive and nanosized Th 1‐ x Y x O 2‐ x /2 or Ce 0.8 Ln 0.2 O 1.9 mixed oxides were prepared through the initial precipitation of hydroxide precursors which were further dried under vacuum. Whatever the chemical system investigated, the characterization of the powdered samples evidenced a rapid aging process leading to hydrated oxides. The thermal behavior of these samples was further investigated and first showed a two‐step dehydration process, with the successive departure of adsorbed and constitutive water, both yielding a drastic drop of the powders’ reactivity (i.e. decrease of the specific surface area). Sintering experiments were then undertaken by starting directly from raw powders and revealed very rapid densification kinetics. Highly densified pellets (above 95 %TD) with a fine grain microstructure were obtained after only 1 hour of heat treatment at 1600 °C. This easy and versatile process of precipitation, that can be followed by direct densification of the powders, then appears as a promising option for the elaboration of homogenous ceramic electrolytes.