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 degreesC; the grains were angular at 1390 degreesC and corner-rounded at 1420 degreesC. At 1390 degreesC, a few very large grains appear in the microstructure. Such abnormal grain growth is explained in terms of a coarsening advantage due to the Sigma3 coincident site lattice (CSL) boundaries. On the other hand, at 1420 degreesC, normal grain growth was observed to occur. The change in coarsening behavior with temperature is related to the structural transition of the interface.close7