Nonlinear dielectric susceptibility of KCl:OH dipole glass

Abstract

The nonlinear dielectric permittivity of KCl:PH (0.2%) is reported from 0.15 to 4.2K from 34 Hz to 34 kHz and in bias fields E up to 500 kV m-1. Below 1K the permittivity is markedly time dependent after any change of bias, but above 2K in the Curie-Weiss regime a stable value is rapidly obtained. Expanding the permittivity in even powers of E, the values of the E2- and E4-terms are respectively one and two orders of magnitude higher than those calculated from the normal saturation effect, which the authors attribute to clustering of dipoles by analogy with superparamagnetism. They find no evidence for a critical behaviour.