Dynamical properties, sequence and mechanism of the phase transition and non-linearities in ABO3 ferroelectrics

The paper proposes a comparative analysis of the relations between the lattice dynamics, both of phononic and relaxational character, the structural phase transitions, their nature and sequence, as well as the ferroelectric properties of several ABO3 solid solutions. These considerations are illustrated by significant experimental and theoretical results obtained on pure and mixed perovskite oxides such as KTa1-xNbxO3, BaTiO3, AgTa1-xNbxO3 and PbZr1-xTixO3. The origin of the non-linear terms in the dielectric susceptibilities, their dispersive behaviour and their magnitude are discussed.