Application of the Intergranular Impedance Model inCorrelating Microstructure and Electrical Propertiesof Doped BaTiO_3

摘要

Microstructure properties of barium-titanate based materials, expressed in grainboundary contacts, are of basic importance for electric properties of this material. In thisstudy, the model of intergranular impedance applied on a two-grain contact is considered.Globally, a BaTiO_3-ceramics sample consists of a large number of mutually contacted grains,which form clusters. Such clusters can be presented as specific fractal formations. For eachof them, it is possible to establish the equivalent electrical model and, for a defined set ofinput parameters, using symbolic analysis, obtain the frequency diagram. The influence offractal structure is especially stressed. Realizing the totality of relations between cluster graingroups, their microelectrical schemes and corresponding frequency characteristics, on onehand, and the global equivalent electrical scheme and corresponding acquired frequencycharacteristics of BaTiO3-ceramics samples, on the other hand, we set a goal of correlatingexperimental results with the summing effect of microelectric equivalent schemes. The modelis successfully tested on doped barium- titanate ceramics.