Optically accessible electrodynamic levitator for in-situ LIBS characterization of iron particles under reactive conditions

This study presents an optically accessible electrodynamic levitator that enables quantitative single-particle analysis using laser-based diagnostics. In the context of thermochemical energy storage, the oxidation behavior of individual iron (Fe) microparticles is investigated. Laser-induced breakdown spectroscopy (LIBS) is further developed to determine the particle-specific oxygen-to-iron (O/Fe) ratio in-situ, providing direct insight into the surface composition during oxidation. Diffuse backlight-illumination (DBI) is applied in parallel to visualize the laser pulse-particle interaction and plasma dynamics. The defined, contact-free particle positioning achieved by the electrodynamic levitator ensures reproducible laser coupling, stable plasma conditions, and improved quantitative accuracy compared to previous free particle jet analyses (Fe, Fe 2 O 3 ). The electrodynamic levitator enables highly repeatable positioning of microparticles (Fe, Fe 3 O 4 , Fe 2 O 3 ), regardless of their morphology and composition, which represents an important step in the diagnostic development for the analysis of reactive particles.