Abstract: Nanometer-sized antimony-doped tin oxide powders were prepared by coprecipitation using SnCl₄·5H₂O and SbCl₃ as starting materials. The characteristics
of the powders were investigated by X-ray diffraction (XRD), transmission electron microscope (TEM) and differential thermal analysis (DTA). The influences of antimony
concentration on the phase, particles size and powders resistance were researched. The results indicate that samples with lower Sb concentration(x≤0.462) are
tetragonal SnO₂ phases with Sb atoms as the solute in the lattice while Sb atoms are separated from tetragonal SnO₂ phases and oxidized into Sb₂O₄
phase in samples with higher Sb concentration(x≥0.519); Doped Sb plays the role of reducing SnO₂ crystallite size and restrains the crystallite growth
during heat treatment, and the particle size is insensitive to Sb concentration when Sb concentration is above 0.181; the electric conductivity of SnO₂ powders
increases with increasing Sb concentration and reaches a maximum at x=0.095, and the resistance of samples increases rapidly at x>0.245. The optimal range of
Sb concentration is 0.181～0.230.

Key words: nanometer-sized antimony-doped tin dioxide powders, antimony concentration, properties of antimony-doped tin dioxide powders