DIELECTRIC AND MICROSTRUCTURAL PROPERTIES OF SINTERED BATIO3 CERAMICS PREPARED FROM DIFFERENT TIO2 RAW-MATERIALS

BaTiO3 ceramics, sintered from powders previously synthesized using TiO2 of different characteristics, have been studied. The microstructural development depended on the crystalline nature and impurity types and levels, when the same sintering schedules were applied. Anatase leads to BaTiO3 powders which showed a controlled grain growth after sintering. Rutile with very low impurity levels gave materials in which a non-uniform grain growth was promoted. Dielectric constant and loss tangent were measured and correlated with the density and microstructure. From these correlations, it seems that the raw materials' nature has a greater effect on the dielectric properties that the sintering schedule of a given material.