The correlation effects in the disordered ferroelectrics

摘要

The calculation of the correlation radius distribution function is performed for the cases of undamped and overdamped soft mode dispersion laws. Taking into account the correlation radius dependence on the random field and this field distribution function we carried out the theoretical calculation of the correlation radius distribution function dependence on temperature, damping coefficient and random field distribution function parameters. It was shown that at temperature higher than Burns temperature T_d the most probable value of the correlation radius is equal to its maximal value independently on the system disorder, while in the dipole glass state it is close to the minimal value with broad tail of distribution function existing at broad temperature region.