Intrinsic effective elastic tensor of ferroelectric polycrystalline lead titanate based thin films with fiber-type texture

The intrinsic effective elastic tensor of polycrystalline lead titanate based thin films with mixed <001>,<100> fiber-type texture has been calculated by a volume average of the elastic coefficients of the individual crystallites, taking into account their actual crystallographic orientation relative to the film reference system. This is introduced in the calculations through an orientation distribution function, which is obtained by the quantitative analysis of experimental X-ray pole figures using a recently developed method: the combined approach. PbTiO3 single crystal data have been used in the calculations. The elastic anisotropy of the single crystal tensor is strongly reduced for the textured thin films and depends on the relative contributions of the <001> and <100> texture components, being only negligible when both contributions are similar. The results presented in this work, and that can be applied to any other textured films with different compositions, contribute to the knowledge of the effective elastic tensor of these ferroelectric films, an important class of materials used in micro-electro-mechanical-systems, which is essential for the design of the devices.