THE INFLUENCE OF CONSOLIDATION PARAMETERS ON GRAIN CONTACT SURFACES BaTiO_3-CERAMICS

摘要

Among the modified BaTiO_3 La doped BaTiO3-ceramics are intensively studied because of their attractive ferroelectric properties that can be tailored to meet the strong demands for various electroceramic components. In this investigation La/Mn codoped BaTiO_3 with different La_2O_3 content, ranging from 0.1 to 5.0 at% La, was investigated regarding their microstructural characteristics. Microstructural and compositional studies were performed by scanning electron microscopy (JEOL-JSM 5300) equipped with EDS (QX 2000S) system. Depending on the amounts of dopants and sintering temperature a huge range of microstructure features can be observed in doped ceramics, together with the appearances of secondary phases that are formed above eutectic temperature. The morphology of ceramics grains pointed out the validity of developing new structure analytical methods, based on different grains' shape geometries. The new correlation between microstructure of doped BaTiO_3-ceramics, based on fractal geometry and contact surface probability, has been developed. Using the fractals and statistics of the grains contact surface, a reconstruction of microstructure configurations, as grains shapes or intergranular contacts, has been successfully done. The directions of possible materials properties prognosis are determined according to the correlations synthesis-structure-property.