| 초록 |
Nanostructured materials are currently receiving much attention because of their unique structural and physical properties. Research has been stimulated by the envisaged applications for this new class of materials in electronics, optics, catalysis and magnetic storage since the properties derived from nanometer-scale materials are not present in either isolated molecules or micrometer-scale solids. This study presents the experimental results derived from the various functional materials processed in nano-scale using pulsed laser ablation, since those materials exhibit new physical phenomena caused by the reduction dimensionality. This presentation consists of three main parts to consider in pulsed laser ablation (PLA) technique; first nanocrystalline films, second, nanocolloidal particles in liquid, and third, nanocoating for organic/inorganic hybridization. Firstly, nanocrystalline films were synthesized by pulsed laser deposition at various Ar gas pressures without substrate heating and/or post annealing treatments. From the control of processing parameters, nanocystalline films of complex oxides and non-oxide materials have been successfully fabricated. The excellent capability of pulsed laser ablation for reactive deposition and its ability to transfer the original stoichiometry of the bulk target to the deposited films makes it suitable for the fabrication of various functional materials. Then, pulsed laser ablation in liquid has attracted much attention as a new technique to prepare nanocolloidal particles. In this work, we represent a novel synthetic approach to directly produce highly-dispersed fluorescent colloidal nanoparticles using the PLA from ceramic bulk target in liquid phase without any surfactant. Furthermore, novel method based on simultaneous motion tracking of several individual nanoparticles is proposed for the convenient determination of nanoparticle size distributions. Finally, we report that the GaAs nanocrystals is synthesized successfully on the surface of PMMA (polymethylmethacrylate) microspheres by modified PLD technique using a particle fluidization unit. The characteristics of the laser deposited GaAs nanocrytals were then investigated. It should be noted that this is the first successful trial to apply the PLD process nanocrystals on spherical polymer matrices. The present process is found to be a promising method for organic/inorganic hybridization. |
