Impedance Spectroscopy: Concepts and Applications

Impedance spectroscopy is a technique that allows to characterize electrically materials, in particular the polarization mechanisms, that is, the charge migration and the orientation of permanent dipoles. To obtain a complete characterization of the dielectric response, a huge range of frequencies and temperatures must be used. The different regimes of the dielectric function can be observed and the dynamics of the relaxations can be found. In this chapter, different examples of using impedance spectroscopy to characterize materials are presented, showing the capability of this technique. Grains and grain boundaries can be identified, and several equivalent circuits are discussed. Performances that permit to investigate the fundamental aspects of the electrical properties are presented, yielding a wealth of information about the molecular motions and relaxation processes present in different materials.