Dielectric spectroscopy and techniques

Dielectric spectroscopy (DS) has been recognized as an experimental technique for the last 60 years for the study of relaxation phenomena in complex materials. Despite its illustrious history (the first dielectric experiments can be assigned to Michael Faraday), it is less known than other techniques, such as rheology and X-ray diffraction analysis. However, in recent years its popularity has rapidly grown. In this article, we present the fundamental theoretical underpinning of DS as well as the current models used to describe molecular dielectric relaxations. The various measurement techniques are briefly summarized and broadly split into the time-domain and frequency-domain approaches. Importantly, different sample/sensor configurations and pitfalls in measurements are considered, including Electrode polarization effects. A worked experimental example is provided to illustrate the concepts discussed in the chapter.