Fast Dynamics of Glass-Forming Glycerol Studied by Dielectric Spectroscopy

Dielectric spectroscopy up to 370 GHz has been performed on supercooled glycerol for temperatures between 250 and 330 K. The high-frequency dielectric loss, ${\varepsilon }^{\prime \prime }$, has been investigated by coherent-source submillimeter-wave spectroscopy. Special attention is given to the dielectric loss in the crossover regime from the structural relaxation to the far-infrared response. A minimum is observed in ${\varepsilon }^{\prime \prime }\left(\nu \right)$ which is compared to theoretical concepts that predict fast relaxational processes.