Optimizing a high-pressure synthesis protocol for producing high-performance thermoelectric skutterudite materials using in-situ XAS and SXR

The objective of this project is to investigate the stability and phase formation of Co4Sb12 skutterudite during the HP-HT synthesis at relevant conditions (3.5–7 GPa; 800–900 °C). Developing new thermoelectric materials with competitive performance is a necessary step forward to enable an ecological transition based on clean energy generation and green mobility. Recently, our group has developed a novel HP-synthesis protocol (piston-cylinder press) to obtain Sr0.5Co4Sb12, that exhibit an ultra-low thermal conductivity (< 2 W·m-1·K-1) and thus enhance the thermoelectric performance. We intend to replicate this method in a diamond anvil cell (DAC) and follow it in-situ based on both time-resolved XAS and SXRD data. With this experiment, we can: (i) gain a deeper and new understanding of the synthesis process itself, in particular of the induced phase formation; (ii) refine the preparation method and adjust the parameters to further reduce the final device operating temperature.