A Comparison of the Thermodynamic and Series Capacitance Analysis of the Electrode-Film Interface on the Dielectric Behavior of Ferroelectric Films—Ba_0.4Sr_0.6TiO₃

Abstract

The dielectric constant of Ba_0.4Sr_0.6TiO₃ films exhibited both bias field dependence and thickness dependence. In thin films, the electrode-film interface influences the dielectric behaviour. This interface is analysed by two methods: Conventionally the film-electrode interface has been explained in terms of a barrier layer at the film electrode interface. An alternative method is to introduce an electrode-dielectric interface energy to the Devonshire phenomenology to describe the thickness dependence of dielectric constant. The existence of barrier is established which influences the measured value in films, but it is not exactly possible to pinpoint its origin and eliminate its effect by theoretical models.