INTERMEDIATE PHASE BETWEEN DEUTERON-GLASS AND ANTIFERROELECTRIC ORDERIN THE D-RADA SYSTEM

This paper reports the results of a dielectric investigation of deuter ated glass D-RADA, x = 0.39. The shape of the temperature dependence o f the imaginary part of the permittivity epsilon'' was analyzed, Analy sis of the shape of the temperature dependence of epsilon''(T, nu) pro ved the existence of two phases of different mechanisms of relaxation, forming among the antiferroelectric domains. One of these mechanisms can be described by the Vogel-Fulcher equation with the parameters T0 = 25.7 K, E(c) = 105.6 K (9.1 meV) and nu0 = 1.16 x 10(8) Hz, and is t ypical for clusters with short-range order characteristic of proton (d euteron) glass. The other relaxational mechanism is the thermally acti vated Arrhenius dipolar reorientation with activation energy E(c) = 11 05 K (95.2 meV) and frequency nu0 = 1.44 x 10(12) Hz. It is related to free dipoles which have been released from the melting long-range ord ering but have not managed to form a cluster yet.