Structural and morphological transformations of BaTi[O.sub.3] nanocrystals in thin layers of borate oxide glasses

The influence of thin layers (2-15 µm) of some oxide glass melts on BaTi[O.sub.3] nanocrystallites has been investigated using X-ray diffractometry and scanning electron microscopy. It has been shown that lead borate and sodium borate glass melts bring about the dissolution of BaTi[O.sub.3] nanocrystallites and the subsequent crystallization in glasses of lead titanate PbTi[O.sub.3] and sodium titanate [Na.sub.2]Ti[O.sub.3], respectively. It has been found that thin layers of melts of these glasses have a strong orientation effect on crystallites of the PbTi[O.sub.3] and [Na.sub.2]Ti[O.sub.3] compounds newly synthesized from barium titanate. The orientation effect exerted by these glass layers results in the formation of a pronounced texture of the perovskite crystallites with the texture axes oriented along the [100] and [001] directions parallel to the surface normal of the substrate for lead titanate and the orientation of the (211) planes of the film surface for the sodium titanium oxide.