Low-Temperature CVT Sintering of In2O3:Sn Ceramics

A novel approach for sintering In₂O₃ ceramics using chemical vapor transport based on chlorine as a transport agent has been developed. Thermodynamic analysis has shown that this transport agent is the most promising among halogens for low-temperature sintering. The vapor phase composition of In₂O₃−MeO₂−Cl₂ (Me = Si, Ti, V, Ge, Zr, Sn, Ce, Hf) CVT systems has been calculated, and it has been shown that Cl₂ should promote a fast dissolution rate of SnO₂ and GeO₂ dopants in ceramics. It has been experimentally demonstrated that in the case of using Cl₂, a dense gaseous medium of In- and Sn-containing species is formed, which contributes to high uniformity of indium-tin oxide ceramics. The advantages of the proposed sintering method consists in: low sintering temperature of 800°C, increase in density by 20–30%, possibility of a decrease in resistivity by a factor of 10², higher thermal stability of CVT ceramics, as well as higher structural perfection of thin films deposited by high-power magnetron sputtering.