The Process of Particle Formation in the Flame Synthesis of Tin Oxide Nanoparticles

Tin oxide nanoparticles with sizes in the range 5-30 nm are generated within a low pressure flame reactor setup in the gas phase. We study the effect of preparation parameters such as precursor concentration, flame to substrate distance, and post-deposition annealing procedures on the morphology and crystal structure of the particles utilizing transmission electron microscopy and X-ray diffraction in order to characterize the particle formation process. The structural investigations indicate that monoxide particles form from SnO monomers within the flame. These primary particles need to be further oxidized and thermally annealed to transform into single phase rutile type SnO₂ nanoparticles.