Effects of solutes on the grain boundary mobility of TiO sub 2.

We measured the grain growth kinetics of TiO sub 2 with different types and concentrations of dopants. In particular, we investigated two aliovalent dopants, namely Nb and Al; and two isovalent dopants, namely Sn and Zr, with dopant concentrations from 0 to mole %. Grain boundary mobilities of undoped and doped TiO sub 2 were measured from the grain growth kinetics. We observed that the grain boundary mobility of TiO sub 2 was increased ~4.8 times by 0.1 - 1.0% Al and decreased 9 times by 0.5% Nb. The isovalent dopants investigated in this study had a smaller effect on the grain boundary mobility of TiO sub 2.