Abstract
Microstructures of Sn-doped sintered indium oxide were investigated by transmission electron microscopy. It was found that Sn-rich nanosized precipitates were formed inside the ITO grains, in addition to the secondary phases of In4Sn3O12 formed at grain boundaries. By nano-beam electron diffraction analysis, the crystal structure of the nanosized precipitates was determined to be the fluorite structure, which is different from the bixbyite structure of the ITO matrix. The structural change in the Sn-rich nanosized precipitates can be explained by the insertion of O2− ions in the vacancy sites of the bixbyite structure during the substitution of In3+ sites by Sn4+.
