Preferential grain growth in the solid-phase crystallization of amorphous SrB2TaO9 thin films prepared by metal-organic decomposition

Abstract

We studied the crystallization process of amorphous SrBi2Ta2O9 (SBT) thin films by transmission electron microscopy. The amorphous SET films were prepared by the metal-organic decomposition method and were heat-treated at 800 degrees C in a dry O-2 ambient. Through a (001) projection, a circular grain was formed showing no preferential orientation of SET grain. On the other hand, through a (110) projection, an elliptical nucleus oriented to another (110) direction was formed. Grain with another orientation also offered evidence of 110-preferred growth. The (110)-preferred growth can be explained by the fact that the highest ionic packing plane is the (001) plane including TaO6 octahedra and the nearest bonding direction of the TaO6 octahedra in an SET structure is the (110) direction.