Effect of ambient gas conditions on laser-induced copper plasma and surface morphology

The effect of different gases and their pressures on the intensity of spectral emission, electron temperature and density of laser-produced plasma has been investigated. For this purpose, Cu targets were ablated by employing Q-switched Nd:YAG laser pulses (λ~1064 nm, τ~10 ns, pulsed energy of 200 mJ) under various filling pressures of the background gases argon, air and helium. The optical emission spectroscopy of Cu plasma has been studied using the laser-induced breakdown spectroscopy system. The results obtained strongly indicate that the nature and pressure of the ambient atmosphere are one of the controlling factors of the plasma characteristics. A scanning electron microscopy analysis has been performed to investigate the dependence of surface morphological changes of an irradiated target on the nature and pressure of an ambient gas. The basic aim of this study is to improve the understanding of ablation mechanisms and plasma parameters (optical emission intensity, electron temperature and density) under various ambient conditions. The optimization of experimental conditions (the nature and pressure of the ambient environment) is very important for temperatures and densities of ablated species, which are consequently crucial for pulsed laser deposition of thin films and nanostructuring of materials.