Grain Boundary Chemistry and Microstructure of Semiconducting Ceramics Prepared from Surface-coated Powders

초록

The relation between the microstructural and chemical characteristics of the grain boundaries in polycrystalline SrTiO3 and BaTiO3 ceramics, prepared from surface-coated semiconducting powders by hot-pressing techniques, has been investigated. The interplanar spacing near the grain boundary is different from that of the inner region of the grains, mainly due to the distribution of chemical composition near the grain boundary. It indicates that Mn ions, which were coated on the surface of powders and are present at grain boundaries, varied the interplanar spacing near the grain boundary, compared to that of the inner grain region. The structural characteristics of grain boundareis can also be controlled by adjusting the chemistry of the grain boundaries with particular amounts of the coating materiasl on the surface of the semiconducting powders.