1. Synthesis and Direct Sintering of Nanosized (M IV ,M III )O 2‐ x Hydrated Oxides as Electrolyte Ceramics
- Author
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T. Cordara, Nicolas Dacheux, Laurent Brissonneau, Fabienne Audubert, Julien Martinez, Y. Cherkaski, Nicolas Clavier, and Sophie Costis
- Subjects
Materials science ,Inorganic chemistry ,Oxide ,Sintering ,02 engineering and technology ,Electrolyte ,010402 general chemistry ,021001 nanoscience & nanotechnology ,Microstructure ,01 natural sciences ,Atomic and Molecular Physics, and Optics ,0104 chemical sciences ,chemistry.chemical_compound ,Adsorption ,chemistry ,visual_art ,Specific surface area ,visual_art.visual_art_medium ,Hydroxide ,Ceramic ,Physical and Theoretical Chemistry ,0210 nano-technology - Abstract
Highly reactive and nanosized Th1-x Yx O2-x/2 or Ce0.8 Ln0.2 O1.9 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.
- Published
- 2017