Geometrical Polarization Approach method applied to A(BB")O₃ complex perovskites

The geometric polarization approach (GPA) method is proposed to obtain the intrinsic polarization of polar dielectrics with complex A(B'B '')O-3 perovskite structure. The aspects related to the aliovalent site occupation (B', B") in this kind of complex perovskites are presented, discussed and analyzed aiming at its application in GPA. The GPA method is applied to determine the intrinsic polarization of Pb(Zr0.6Ti0.4)O-3 (PZT60/40, rhombohedral, R3m space group) and Pb(Zr0.4Ti0.6)O-3 (PZT40/60, tetragonal, P4mm) compounds at room temperature as prototype phases of polar dielectrics with complex A(B'B '')O-3 perovskite structure. The intrinsic polarizations, 49 mu C/cm(2) and 45 mu C/cm(2) for PZT60/40 and PZT40/60 compounds, respectively, as signatures of the polar state and in complete agreement with previous reports, are obtained from the off-centering position of the total negative and positive electric charges at the unit cell.