Temperature dependence of the coarsening behavior of (Ba, Sr)TiO3 grains dispersed in a SiO2-rich liquid matrix

The shape of (Ba0.35Sr0.65)TiO3 (BST) grains and their coarsening behavior were investigated as a function of temperature. The BST grains exhibit a morphological change at approximately 1410 °C; the grains were angular at 1390 °C and corner-rounded at 1420 °C. At 1390 °C, a few very large grains appear in the microstructure. Such abnormal grain growth is explained in terms of a coarsening advantage due to the Σ3 coincident site lattice (CSL) boundaries. On the other hand, at 1420 °C, normal grain growth was observed to occur. The change in coarsening behavior with temperature is related to the structural transition of the interface.