PNNL

Abstract

The evolution from gas-phase oxidation to nanoparticle and agglomerate formation was studied in nanosecond laser-produced plasmas of a multi-principal element alloy target in air. Gas-phase oxidation of plasma species was monitored in-situ via optical emission spectroscopy, while a custom-built single-particle mass spectrometer was used to measure size and compositions of individual particles formed in laser ablation plumes. Ex-situ analysis employing transmission electron microscopy revealed nanoparticle morphology, crystal structure, and element distribution at the nanoscale. Our findings highlight that the heterogeneous nature of laser-produced plasmas and target composition influence particulate material generated via laser ablation.