Dynamic dielectric susceptibility of the betaine phosphate (0.15) betaine phosphite (0.85) dipolar glass

Abstract

Dielectric susceptibility measurements in a wide frequency spectrum were used to obtain the distribution of relaxation times. This was performed by solving the integral equation for the susceptibility with the Tikhonov regularization technique. This method allows to extract the distribution of the relaxation times and resolves multiple dynamical processes. As an experimental example the investigation on mixed crystals of protonated and deuterated ${\mathrm{BP}}_{1\ensuremath{-}x}{\mathrm{BPI}}_{x}$ with $x=0.85$ are presented. The dipole-freezing phenomena results in a broad asymmetrical distribution of the relaxation times. The parameters of the double-well potentials of the hydrogen bonds, the local polarization distribution function and the glass order parameter have been extracted from the dielectric measurements. The microscopic parameters obtained are in good agreement with magnetic resonance data.