IMF2017

The most physical characteristics of artificial layered structures – ferroelectric superlattices (Curie temperature, the spontaneous polarization, and the dielectric constant of its nonlinear field dependence) change significantly compared to single-layer materials. To determine the influence of size effects on the properties of ferroelectric superlattices in the present work we have investigated the dielectric properties of the superlattices with 32 layers of barium zirconate - titanate BaZrO₃ / BaTiO₃ on LaSrCo/MgO substrate with a thickness of the individual layers of 6.65 nm/7.506 nm, obtained with using of pulsed laser deposition. Carried out research of the temperature dependence of dielectric constant showed the presence of anomalies with a maximum dielectric constant ̴ 200, corresponding to a phase transition with temperature ̴ 400 ^o C lying between the Curie points of the lattice components, thus indicating the emergence of a qualitatively new structure as compared with the initial components. Using a modified scheme Soyer - Tower with conductivity compensation, the dependencies on the coercive field and spontaneous polarization on temperature were obtained. The temperature dependence of polarization in the vicinity of the transition temperature changes rather smooth, which may be due to the ingomogeneity of the synthesized structure. Synthesized superstructures have little internal bias field in comparison with its coercive one. Experimental studies of the dynamics of switching processes in synthesized superlattices with using Merz techniques revealed the transition from the "creep" regime with an activation of switching processes to slip regime at field ̴ 300 kV/cm.