Chemically induced interface migration (CIIM) in the $SrTiO_3$ and $BaTiO_3$ system has been investigated. $SrTiO_3$ powder compact has initially been sintered at 1450'C for 4 h in air. The sintered body has been packed by CaO, MgO or $BaTiO_3$ powder, and annealed in air at various temperatures (1100'C-1400'C) and for various times (20 h-160h). In most of the specimens, grain boundary migrates from the original boundary between grains, forming new solid solution containing cations of packing powder. Wiggling and serrating of the grain boundaries have also been observed. In the specimens packed with CaO powder, the migration distance is linearly proportional to annealing time. These experimental results can be explained by CIIM.
$BaTiO_3$-0.3%$La_2O_3$-5.7%$TiO_2$ powder compact has been sintered at 1430'C for 4 h in reducing atmosphere ($H_2$ or $H_2+N_2$) and then annealed in various atmospheres (air, $N_2$, $H_2+N_2$,$H_2$) between 1430'C, sintering temperature, and 1200'C for various time (2 h-16 h). Double layer boundary structure of grains has been observed in all the specimens. Measured thickness of the layer increases with annealing time, however, not linearly proportional to the time. The possibility of chemically induced migration of the boundary is discussed.
