Grain growth in BaTiO3 ceramics assisted by an intergranular glass film

Abstract This research demonstrates that BaTiO 3 ceramics exhibit increased grain boundary mobility ( M b ) triggered by an inter-granular glass film (IGF) as previously demonstrated in polycrystalline Al 2 O 3 ceramics conversion to single-crystal sapphire upon annealing at high temperatures. These results suggest that secondary abnormal grain growth (SAGG) during sintering of BaTiO 3 ceramics at 1365 °C, a temperature above the eutectic points in the BaTiO 3 –SiO 2 and BaTiO 3 –TiO 2 systems, is another example of faster M b caused by IGF. Higher M b magnified through an interface glass film of several nanometers thickness facilitates a faster grain growth rate that produces exceedingly large grains of ∼2.4 mm in size. The growth mechanism involving twin-plane re-entrant (TPRE) corners may not be the only route responsible for SAGG in BaTiO 3 , particularly when sintered at above eutectic temperatures. How this abnormal grain growth occurs through mechanisms involving liquid-phase-enhanced M b and the {111} twins as a chemically induced growth fault is discussed.