Multi-scale structural evolution of a thermoelectric selenide upon densification

Thermoelectric (TE) materials, which allow the conversion of heat into electricity, are promising candidates for sustainable energy conversion technologies. Layered compounds such as non-stoichiometric ZrSey (y≈2) appear as a potential TE material. This proposal aims (i) to better characterize the controversial real structure at different length scales of as grown ZrSey (y≈2) synthesized with different nominal selenium content and (ii) to study the impact of the densification process (Spark Plasma Sintering) prior to measuring the TE properties on those multi-scale structural properties. High energy powder X-ray diffraction data coupled to PDF analysis and XAS data will allow to clarify the multi-scale structure, true stoichiometry and zirconium oxidation state of three representative ZrSe2-d as grown (dnominal≅0.14, 0.10, 0.06) and SPS-processed samples. Our ultimate goal is to improve the understanding of the structure-TE properties relationship in ZrSe2-d.