Kinetics of Phase Transformation in the TiO ₂ ‐SnO ₂ System Outside the Coherent Spinodal: Role of Aliovalent Dopants

Abstract

The kinetics of phase transformation in the TiO 2 ‐SnO 2 system above the coherent spinodal is examined with small additions of Al and Ta as dopants. Al increased the rate of phase separation while Ta suppressed it. Precipitation in the undoped sample occurred by cellular mechanism while in the Al‐doped sample it seems to have occurred by heterogeneous nucleation and growth mechanism at the grain boundaries of the original solid solution.