Dynamical Dielectric Instability of the Ferroelectric AgNa(N02)2

The characteristic ferroelectric dispersion of the complex dielectric constant of AgNa(N02)2 is measured in a wide temperature range enclosing the transition point. It can be well described by a Debye monodispersive process except for a small temperature intervall around Tc . The relaxation strength obeys a Curie-Weiss law in the paraelectric phase, whereas in the ferroelectric phase there are deviations from this behaviour. A first order phase transition is observed which is close to a second order one. The maximum value of the dielectric constant at Tc is 104.