Abstract
Semiconductive SnO2 fine powder, doped with Sb, was prepared by a mechano-chemical reaction during dry ball milling. The effects of the crystallinity of the SnO2 starting powder and the revolution rate of the pot mill were discussed in relationship to the doping reaction of Sb in SnO2 during ball milling by taking the milling mechanism into consideration.
The results obtained are the following:
(1) Ball milling at a high revolution rate was effective for the doping reaction of Sb in SnO2, so that the electrical conductivity of the powder mixture ball-milled at such a speed became higher compared with that of the powder mixture ball-milled at a low speed.
(2) When the ball milling was carried out at a high revolution rate using well crystallized SnO2, the doping reaction of Sb was facilitated. However, at the same time, since particle size reduction was significant, the increase in the electrical conductivity was prevented. Thus, when the SnO2 starting powder was used, with a medium degree of crystallinity, the increase in the electrical conductivity was greatest due to competition between the particle size reduction and Sb doping reaction in SnO2.
