Role of liquid phase in achieving a fine microstructure and diffusive phase transition of MgO-Doped BaTiO₃

Two types of glass compositions, with MgO and CaO modifiers, respectively, were used to promote liquid-phase sintering of 2 mol% MgO-BaTiO₃ at 1280°C in reducing atmosphere ( pO₂ = 10^-9 atm). By combining the observations of the grain size of about 1 μm for both specimens and the diffusive phase transition only when MgO modifier was used, it has been interpreted that an appropriate solubility of BaTiO₃ is necessary to yield the fine and composite microstructures via a dissolution-reprecipitation process. Further, a reasonable dopant provision to BaTiO₃ has been shown to be required to achieve the diffusive phase transitions.