After antimony doped tin oxide(ATO)precursors were prepared by the sol-gel method

oven drying

microwave drying

vacuuming drying and supercritical fluid drying(SCFD)were used to treat the alcogels of ATO precursors.Weakly agglomerated nano-sized ATO particles with tetragonal phase structure were obtained after dry precursors were annealed at 600℃ under atmosphere.The nanoparticles were characterized by X-ray diffraction(XRD)

field emission scanning electron microscopy(FESEM)

transmission electron microscopy(TEM)and Malvern Zen1600 Zeta sizer.The results showed that ATO particles with tetragonal phase structure were all well crystallized from four drying processes.However

only the ATO powder prepared by SCFD consisted of primary particles weakly attached to each other

and the average size was around 25 nm.The mechanism was that the particles of precursors could keep loose morphology after treatment by SCFD

which was the key to preparing weekly agglomerated nano-sized ATO particles.In conclusion

it was an effective way to avoid the nano-sized ATO agglomeration by SCFD process in the sol-gel method.