Abstract
The existence of a Debye-type ultraslow process in dielectric spectra of bulk polyalcohols and similar
materials has been reported repeatedly in the recent literature. Its loss peak is observed at frequencies
that are decades below those of the primary structural relaxation, in a range where the loss signal is
usually dominated by dc-conductivity or even electrode polarization. We show that this peak originates
from an incomplete filling of the capacitor volume, e.g., as a result of gas bubbles, a situation
that gives rise to a Debye process at the conductivity relaxation frequency of the material, where
the values of storage and loss components of permittivity are identical. The result implies that these
peaks are not endemic to the liquid and can lead to various misinterpretations of the dielectric relaxation spectra. Techniques avoiding the occurrence of such artifacts are discussed. © 2011 American
Institute of Physics.
