On the parameters of the Dixon-Nagel scaling procedure

We derive the condition for the parameters of the Dixon-Nagel scaling procedure which is required to unambiguously define the parameters. In contrast to the published optimization of the scaling parameters, the presented definition allows us to determine these parameters From experimental spectra and, consequently. to apply the sealing procedure to the analysis of experimental results. To discuss the controversy concerning the problem of the scaling parameters, we study the scaling behavior in the central region of the scaling plot for high-pressure broadened dielectric spectra. The Dixon-Nagel scaling plot for several low-molecular-weight glass-forming liquids is constructed and compared to a plot constructed according to the modified scaling expression we have recently proposed. (C) 1998 Elsevier Science B.V. All rights reserved.