Differential impedance analysis on single crystal and polycrystalline yttrium iron garnets

The resistivity of single crystal and polycrystalline yttrium iron garnet was investigated by the Complex Impedance Method, distinguishing the resistivity of the bulk material from the resistivity of grain boundaries. Two different approaches are used for determination of the model structure: (i) a theoretical in which the structure is assumed a priori as a Voight-type model and (ii) a structural, in which the model is extracted from the experimental data. The second approach is based on recently developed Differential Impedance Analysis. The results obtained illustrate the advantages of the new method, which can give information about the mechanism of the ferrite conductivity and may enhance the knowledge of physical nature of the process. (author)