Spherical particles of undoped and metal-doped tin oxide were prepared by Filter Expansion Aerosol Generator(FEAG). The surface area, crystalline phases and morphologies of the prepared particles were investigated by BET, XRD, SEM/EDAX and TEM. The particle sizes and size distributions of the prepared particles were measured by centrifugal particle size analyser(CPSA) and compared with the results from SEM and TEM. Thermal behavior were also investigated by TGA. The prepared particles had little salt remained in spite of very short residence time of FEAG process. The prepared tin oxide particles by FEAG process showed rather broad particle size distributions from nanosize to about 5㎛.
Undoped and alumina-doped tin oxide particles had tetragonal cassiterite crystalline structures although $ZrO_2$-doped particles had orthorhombic structures. All particles had sufficient BET surface area(29.34~82.55㎡/g) suitable for sensor application. Especially, $ZrO_2$-doped tin oxide particles showed a high dispersion of palladium with large surface area.
