Fabrication of Low‐Porosity Indium Tin Oxide Ceramics in Air from Hydrothermally Prepared Powder

Compositionally homogeneous indium tin oxide (ITO) ceramics with low porosity were obtained successfully by sintering hydrothermally prepared powders. The fabrication technique began with the preparation of microcrystalline, homogeneously tin‐doped (5 wt%) indium oxyhydroxide powder, under hydrothermal conditions. Low‐temperature (∼500°C) calcination of the hydrothermally derived powder led to the formation of a substitutional‐vacancy‐type solid solution of In 2 Sn 1− x O 5− y , and further heating of this phase at temperatures of >1000°C resulted in the formation of the tin‐doped indium oxide phase, which had the C ‐type rare‐earth‐oxide structure. The sintering of uniformly packed, calcined powder compacts at 1450°C for 3 h in air resulted in low‐porosity (∼0.7%) ITO ceramics.