This paper presents a generalized regular singular-point (GRSP) model developed to account for dielectric spectra of the wide range of materials having a frequency response containing more than two power-law regions. In fact, the model is valid for an unlimited number of such regions, and is shown to provide a good description of the entire dielectric spectrum of tablets made of microcrystalline cellulose, including two relaxation peaks and power-law responses at low and high frequencies. This finding puts the GRSP model in a unique position, since no model existing in the literature is able to describe the totality of features present in the spectrum, without resorting to a superposition of more elementary responses.

• Received 30 January 2004

DOI:https://doi.org/10.1103/PhysRevB.70.012506