Influence of Liquid Phase on Grain Growth of Ba0.998La0.002TiO3 Ceramics

The influence of liquid phase on grain growth of Ba0.998La0.002TiO3 ceramics with a different concentration of excess of 2.0% TiO2 sintered at a temperature of 1350 °C was investigated. The results showed that a small amount of Si and P, which came from the raw materials of BaCO3 and TiO2 powders during the liquid phase sintering of Ba0.998La0.002TiO3 ceramics. On one hand, the liquid phase must present during grain growth, on the other hand, BaTiO3 grains must be dissolved, then precipitated from the liquid phase during the process of dissolution-precipitation, otherwise, the grain growth would be inhibited. The liquid phases of Ba6Ti17O4 and Ba2TiSi2O8 promoted grain growth due to high solution of BaTiO3 grains in the liquid phases. Compared with that, Ba2Ti2SiP2O13 liquid phase inhibited the process since BaTiO3 grains could not dissolve into the phase, consequently the samples show insulating.