Modified Landau-Ginzburg-Devonshire Description of Disordered Ferroelectrics with Static Charged Defects.

The model of static charged clusters, which adequately describes the dielectric hysteresis and permittivity of disordered ferroelectrics with non-isovalent impurities, has been proposed. The main result of paper is modified Landau-Ginzburg-Devonshire equation can be applied to the bulk ferroelectric materials with improper conductivity and movable charge fluctuations near the impurity centers. [ABSTRACT FROM AUTHOR]