Microstructural characteristics of (Pb1−xCax)TiO3 materials

Microstructural characteristics including ferroelectric domain boundaries, atomic ordering and TiO6 octahedron tilting of Pb1−xCaxTiO3 (x=0.3, 0.4, 0.5) were studied and correlated to microwave properties. Using transmission electron microscopy, Pb0.5Ca0.5TiO3 specimens reveal 1/2(1 0 0), 1/2(1 1 0) and 1/2(1 1 1) extra reflections regularly in electron diffraction patterns. Dark-field images show two different wavy boundaries using different extra reflections, and their contrast characteristics were discussed. High-resolution transmission electron microscopic (HRTEM) images exhibit ordering characteristics with 1/2(1 1 1) reflections. However, some regions showing no ordering characteristics also exhibit 1/2(1 0 0) and 1/2(1 1 0) reflections. An octahedron tilting model combined with atomic ordering was constructed to interpret diffraction behavior in Pb1−xCaxTiO3 materials and the relation between microstructures and microwave properties was also discussed.