The solid electrolytes are thought to play a major role in future energetic systems. Among them, oxide ceramics with flurorite structure are particularly important. Correctly doped, their ionic conductivity is high and they are suitable for applications in agressive media or at high temperatures. However, these properties are closely related to their microstructure, thus to their fabrication route.
This thesis proposed to study the relation between the microstructure of two fluorite materials, doped hafnium or thorium oxides, and their behavior in liquid sodium. The influence of grain size, density and impurity contents on the corrosion kinetic in sodium would provide insights on the corrosion mechanisms. The ultimate aim is to optimize the service life of these ceramics in oxygen sensors for sodium based energetics systems (nuclear reactors, solar plants…).
The student should be graduated in materials science. The thesis work will take place at the CEA Cadarache (France, Provence) in collaboration with the Institute of separative chemistry of Marcoule (France, Occitanie). It will be based on previous thesis’ work as in this article : https://doi.org/10.1016/j.corsci.2020.108721 .