UMET - Dielectric relaxation spectroscopy

Dielectric relaxation spectroscopy

A broadband dielectric spectrometer (Novocontrol Technologies Alpha Analyzer) coupled to a high frequencies analyzer (Novocontrol Technologies RF impedance analyzer) can be found in our lab.

This setup allows the measure of permittivity of dielectric materials when submitted to an electric field of frequencies varying from 10-2 Hz to 1 GHz. Thanks to a thermal regulation system (Novocontrol Quatro controller), experiments can be performed between -160°C and 300°C, in isothermal or isochronous mode. Different types of electrodes can be used (parallel plate or interdigitated electrodes).

The knowledge of the response of a material (relaxation) to an electric strain allows, depending on the frequency of the applied field, to determine the characteristic time of the involved relaxational movements and so, to access to information on the molecular mobility of the material under different physical states (liquid, glass, mesophases with orientational or positional disorders…).