Optical emission investigation of laser-produced MgB2 plume expanding in an Ar buffer gas

TL;DR

This study uses optical emission spectroscopy to analyze how argon buffer gas affects the plasma dynamics during laser ablation of MgB2, providing insights for optimizing thin film deposition.

Contribution

It demonstrates the influence of argon buffer gas on plasma behavior and blast wave formation during MgB2 laser ablation, which was not previously characterized.

Findings

Argon gas significantly alters plasma expansion dynamics.

Blast waves form at higher argon pressures.

Excited Mg atom fraction increases with argon pressure.

Abstract

Optical emission spectroscopy is used to study the dynamics of the plasma generated by pulsed-laser irradiation of a MgB2 target, both in vacuum and at different Ar buffer gas pressures. The analysis of the time-resolved emission of selected species shows that the Ar background gas strongly influences the plasma dynamics. Above a fixed pressure, plasma propagation into Ar leads to the formation of blast waves causing both a considerable increase of the fraction of excited Mg atoms and a simultaneous reduction of their kinetic flux energy. These results can be particularly useful for optimizing MgB2 thin film deposition processes.