Impedance spectroscopy utilized to study the spatial distribution of conductivity within capacitors during operation

Impedance spectroscopy is a very powerful tool to characterize and separate physical processes that can occur simultaneously in any material. For parallel plate capacitors, consideration of the modulus has proven to be very effective to study materials that exhibit a spatial variation in conductivity in the direction of the electric field. This was demonstrated with in-situ impedance measurements by monitoring the real-time changes of Fe-doped SrTiO₃ during degradation. It is the purpose of this article to adapt these findings and to highlight the possibility to extract information such as local conductivity from complex modulus data of degraded SrTiO₃.