Sintering of the In2O3-SnO2 system with Bi2O3 additive

The authors reported elsewhere that sintering of indium-tin-oxide (tin-doped In2O3) powders with a relatively large particle size (approx. 3 mu m) was remarkably enhanced by the addition of Bi2O3, whose melting point is lower than the sintering temperature, and that Bi2O3 was finally eliminated from the sintered body to avoid the increase in the electrical resistivity caused by the additive. In the present work, a higher density was obtained at the lower sintering temperature by using a powder mixture of In2O3 and SnO2 with smaller particle sizes; the bulk density (89%, 6.4 g/cm(3)) for pellets with Bi2O3 (1.0 mass%) and sintered at 1300 degrees C was slightly higher than or approximately equal to that (88%; 6.35 g/cm(3)) for pellets without Bi2O3, sintered at 1500 degrees C. The maximum density (96%; 6.8 g/cm(3)) and the lowest electrical resistivity (2.5 x 10(-3) Ohm.cm) were obtained with sintering at 1400 degrees C. The sintering process and the behavior of the Bi2O3 were investigated.