Electron Transport Properties of Composite Ferroelectrics

We study electron transport in composite ferroelectrics --- materials consisting of metallic grains embedded in a ferroelectric matrix. Due to its complex tunable morphology the thermodynamic properties of these materials can be essentially different from bulk or thin-film ferroelectrics. We calculate the conductivity of composite ferroelectrics by taking into account the interplay between charge localization, multiple grain boundaries, strong Coulomb repulsion, and ferroelectric order parameter. We show that the ferroelectricity plays a crucial role on the temperature behavior of the conductivity in the vicinity of the ferroelectric-paraelectric transition.Comment: 6 pages, 3 figure