The main purpose of this research area is to systematically study the role of various control parameters in the formation of ferroelectric domain structures under conditions where, due to rapidly cooling, the crystalline sample is in a very non-equilibrium state and becomes particularly sensitive to too small external actions.Establishing physical regularities of the influence of external thermal, mechanical and electrical actions on the relaxation kinetics in ferroelectrics will allow optimizing the processes of obtaining high-quality precision domain structures in order to improve the nonlinear optical, electro-optical and acoustic characteristics of ferroelectric samples.
Upon rapid cooling of the sample from the high-temperature region (paraelectric phase) to the low-temperature one (ferroelectric phase), the crystalline sample turns out in the thermodynamically nonequilibrium state. As a result, this is accompanied by the spontaneous arise the nuclei of domains in spatial and random places of the sample. The high sensitivity of such a system to even very weak external influences opens wide opportunities to control the process of domain structure formation. However, a thorough study of fundamental aspects of ordering process is necessary to develop the practical recommendations for obtaining the domain structures with a given configuration. Therefore, the issues to be addressed within the proposed area, namely how external thermal, electrical and mechanical effects affect the kinetics of domain structure relaxation, are extremely relevant at the present time.
In order to achieve this goal, it is expected to obtain evolutionary equations describing relaxation processes. Due to the random character of the initial conditions, it is assumed that they will be processed within a statistical approach using correlation theory. Ferroelectrics of the displacement type, such as barium titanate, lead titanate, lithium niobate, are the most common and demanded in the modern domain engineering and will be used as model objects.
The results of the studies to be obtained will allow a more accurate quantitative description of the dynamics of non-equilibrium ferroelectrics of different types. We expect that these results will allow us to develop scientific basics and to propose the new methods of influence the domain structures, which are aimed at improving the physical properties of ferroelectric crystals and should contribute to the successful solution of technological problems of modern photonics.
(Responsible: D.Sc. Leonid Stefanovich)