Fyzikální ústav Akademie věd ČR

Computer simulations based on Ginzburg-Landau-Devonshire theory are used to investigate piezoelectric response of tetragonal BaTiO₃ crystals. We have shown that piezoelectric response of twinned BaTiO₃ increases with increasing density of 90° domain walls. A considerable enhancement of the longitudinal piezoelectric coefficient is predicted for domain sizes below 50 nm. We have also shown that main contribution to the longitudinal piezoelectric coefficient comes from the volume of domains, rather than from the domain wall region [J. Hlinka et al., Nanotechnology 20, 105709 (2009)]. (more...)

Fig. 1: Dependence of the effective longitudinal piezoelectric coefficient on domain size calculated from the response of the ideal 2D laminar domain structure to weak uniaxial stresses applied along the [111] crystallographic direction. The inset shows the geometry of the initial 2D laminate domain structure assumed in the simulations.