Physical properties of Ba$_{0.8}$Sr$_{0.2}$TiO$_{3}$ thin films

The behavior of material constants in ferroelectric Ba$_{0.8}$Sr$_{0.2}$TiO$_{3}$ thin films is studied depending on the misfit strain at room temperature in the context of nonlinear thermodynamic potential of the phenomenological theory. Some constants are found to undergo drastic changes with the alternating strain at the interfaces. The gathered results allow one to evaluate the material constants for a specific film and to outline the direction in searching the ways to synthesize films with the needed properties.