Nanoscale Phase Separation in Ferroelectric Materials

Many materials exhibit nanoscale phase separation, when inside the host thermodynamic phase there arise nanosize embryos of another thermodynamic phase. A prominent example of this phenomenon is provided by ferroelectric materials. The theoretical description of such phase heterogeneous materials is quite challenging, since they are essentially nonuniform, the nonuniformity is random, and often they are quasiequilibrium, but not absolutely equilibrium. An approach is suggested for the theoretical description of phase separated ferroelectrics, consisting of a ferroelectric matrix with nanoscale paraelectric inclusions. The properties of the heterophase ferroelectrics are studied.