Fitting the Excess Wing in the Dielectric -Relaxation of Propylene Carbonate

Abstract.

A novel fit function for the complex frequency dependent dielectric susceptibility is introduced and compared against other fit functions for experimental broadband dielectric loss spectra of propylene carbonate from Schneider et al. Phys.Rev.E, 59 (1999), 6924. The fitting function contains a single stretching exponent similar to the familiar Cole-Davidson or Kohlrausch fits. It is compared to these traditional fits as well as to the Havriliak-Negami susceptibility and a susceptibility for a 2-step Debye relaxation. The results for the novel fit are found to give superior agreement.