Low temperature dielectric relaxation in mixed crystals of betaine phosphate and betaine phosphite

Abstract

Abstract We compare dielectric relaxation in the mixed Betaine Phosphate Phosphite system BP x BPI1-x for x=.40, .70 and .85 at low temperatures. In all cases, broad relaxation peaks were detected below 20K. We present a frequency dependent parameterization based upon the Kohlrausch-Williams-Watts formalism. It is found that the KWW relaxation time is Arrhenius and that β kww is strongly temperature dependent. For the case of x=.85, β kww increases with decreasing temperature.