DETERMINATION OF THE DYNAMICAL PROPERTIES OF FERROELECTRICS USING NONLINEAR TIME SERIES ANALYSIS

Abstract

We investigate the behavior of an experimental electric resonance circuit with a nonlinear capacitor. Triglycine sulfate (TGS) was used as nonlinear dielectric material. This is the most thoroughly investigated ferroelectric with a second-order phase transition. Its static dielectric small signal behavior is well described in the framework of the Landau theory of phase transitions. The dynamic behavior however is strongly related to relaxation phenomena due to switching of domains. Here the theoretical situation is still unclear. By mere data analysis we construct an ordinary differential equation which describes the dynamical behavior of the circuit, and which is simple in the sense of Ockham's razor. The structure of this equation is closely related to the dynamical properties of the ferroelectric. We are therefore able to gain some insights into the dynamical behavior of ferroelectrics, which may give some hints for a more exhaustive analysis of nonequilibrium properties of ferroelectrics.