Nanoparticle generation/manipulation based on pulsed-laser ablation

Ultra fine powders, especially particles less than 100nm in diameter, are becoming increasingly important in a variety of applications that take advantage of the electronic, magnetic, and chemical properties as well as in nanostructured materials having extremely fine grains. Accordingly, a variety of techniques have been proposed for synthesis of nanoparticles. Among them, techniques based on pulsed laser ablation of micron-sized particles in gases or liquids have strong potential for successful applications, because of their simplicity in the synthesis process and narrow size distribution of the generated nanoparticle. Particularly, laser ablation of microparticles(LAM) in air is a simple and effective method. It has been demonstrated that various nanoparticles can be successfully produced by the process. Recently, we also proposed a similar process using laser ablation of consolidated microparticles(LACM). In the LAM or LACM process, it is generally believed that the photomechanical effect induced by the shock results in large mass conversion efficiently from feedstock to nanoparticles, compared to that by thermal evaporation. However, no thorough understanding of the phenomena has yet been achieved and many of the suggested mechanisms require experimental verification, especially for metals and ceramic nanoparticles.

LAM: Laser Ablation of Microparticles

LACM: Laser Ablation of Consolidated Microparticles

Result

Substrate: Al, Cu, Ag microparticles (10-50㎛)
→(laser ablation)→Metal(-oxide) nanoparticles: Al2O3, CuO, Ag (20-500nm)