Determination of self and cross contributions to the dipole–dipole correlations function from analysis of dielectric measurements
Marian Paluch, Kajetan Koperwas, Ż. Wojnarowska
Abstract
The nonexponential nature of the structural relaxation is one of the most characteristic features of the molecular dynamics in glass-forming liquids. Various experimental techniques can be employed to probe this process; however, broadband dielectric spectroscopy (BDS) is the most frequently used. Based on MD simulations, we provide strong evidence of bi-modal nature of the dielectric loss peak of primary relaxation. Further, we point out that the primary dielectric relaxation process measured at constant displacement D is dominated by the self-correlation term in the dipole–dipole correlation function. In practice, it means that the dielectric spectra should be presented in the dielectric modulus representations to disclose the spectral features of the self mode.