26.03.2026 • Contributions

Gas Phase Plasma Transfer in Analysis of Metal Microparticles

With the expansion of renewable energy sources, such as wind and solar, metal microparticles are gaining attention as potential chemical energy storage materials. Laser-induced breakdown spectroscopy (Libs) enables in-situ analysis of the thermochemical oxidation of iron particles by measuring the oxygen-to-iron ratio on the particle surface. A study investigates how laser pulse length affects the surrounding gas phase, which can partially transfer into the plasma and superimpose with the Libs signal emitted from the particle surface.

Metal microparticles have the advantage of high energy density and long potential storage times, making them well suited for storing renewable energy [1]. Iron oxide can be reduced by green hydrogen and later oxidized again to release energy in retrofitted coal fire power pants [2]. In-situ Libs can analyze the atomic composition of surfaces during rapid, high-temperature oxidation, overcoming the limitations of ex-situ or low-time-resolution studies. This data is required for developing combustion-kinetics models. Diagnostics present challenges such as overlapping element spectra from the particle plasma and the surrounding gas that has inadvertently been transferred into the plasma. The data can be distorted by the Lib-spectra of the gas transferred into the plasma which depends on the laser pulse length (nanoseconds vs. picoseconds) and is analyzed in this study.

Laser-Induced Breakdown Spectroscopy – An Overview

Libs uses high-intensity short laser pulses to convert small amounts of target material into plasma for optical analysis. Applicable to solids, liquids, and gases, it can detect elements without contact, enabling measurements without sample preparation and high time resolution.