Metals and metal oxides particles produced by pulsed laser ablation under high vacuum


Abstract: A pulsed KrF Excimer laser (248 nm, 15 mJ) was utilized to synthesize different particles on (111) Si substrate under vacuum \sim 10^{-6} torr using Aluminum (Al), Platinum (Pt), Tungsten (W), Molybdenum (Mo), Cadmium Oxide (CdO), and Yttrium Oxide (Y_2O_3) targets. Scanning electron microscope (SEM) was used to study particle size distribution on silicon substrate. The size of individual metal particles was found to be ranging from 71 nm to 2 \mu m whereas metal oxides particles were found in the range of 71 nm to 1.1 \mu m. The particles below 100 nm are formed by gas phase condensation of ions, atoms and molecules whereas particles greater than 100 nm size results either from the ejection of liquid droplets from the melt surface or stresses induced by laser on target surface. The advantage of particle formation due to laser ablation in high vacuum is pure particles production.

Keywords: Laser ablation, nanoparticles, high vacuum

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