Effects of external mechanical loading on phase diagrams and dielectric properties in epitaxial ferroelectric thin films with anisotropic in-plane misfit strains

The influence of stress on phase diagrams and dielectric properties in epitaxial BaTi[O.sub.3] and PbTi[O.sub.3] thin films grown on the dissimilar orthorhombic substrates is analyzed by using a phenomenological Landau-Devonshine theory. The dielectric properties and the tunability of both the films are studied and it is found that the external stress dependence of phase diagrams and dielectric properties depends on the strain anisotropy.