STUDY OF THE ORDER-DISORDER TRANSITION IN A(B'B'')O3 PEROVSKITE TYPE CERAMICS

Based on an order-disorder transition model and the calculation of coulombic electrostatic interaction of B-site ions, an "ordering structure factor" F0 is introduced. Consequently, an available criterion and diagram to predict the order-disorder transition of A(B'B")O3 is presented quantitatively. The theoretical results compare satisfactorily with experimental data collected from the literature for different kinds of A(B'B")O3 ferroelectrics and antiferroelectrics. Permittivity epsilon' is a sensitive parameter and plays an important role in order-disorder transition. The reason for conflicting arguments from different references for the ordering of some compounds is discussed.