Using of mechanical deformations to control for phase transformations in multilayer ferroelectric structures

Based on the results of studies of the temperature dependences of dielectric constant, polarization and coercive field, the Curie points and the type of phase transition for three-layer ferroelectric structures barium titanate – strontium titanate SrTiO$_3$/PbTiO$_3$/SrTiO$_3$ and lead titanate – strontium titanate SrTiO$_3$/PbTiO$_3$/SrTiO$_3$ were determined. It is shown that in a multilayer with barium titanate there is a significant (about two hundred degrees) increase in the Curie temperature of the created structure compared to homogeneous barium titanate, and the type of ferroelectric phase transition changes from first order to second order. In a multilayer with lead titanate, the Curie point and the type of transition practically do not change in comparison with homogeneous lead titanate, which is associated primarily with the practical coincidence of the cell sizes of lead titanate and strontium titanate in the plane of contact.