Microstructure and orientation relations of BaTiO₃/MgO/YSZ multilayers deposited on Si(0 0 1) substrates by laser ablation

The microstructure and crystallographic relations in BaTiO₃/MgO/YSZ multilayer films deposited on Si(0 0 1) substrate are investigated by means of transmission electron microscopy. On Si(0 0 1) substrate the YSZ layer grows epitaxially with a cubic-to-cubic orientation relationship. The MgO layer is columnar-grained and exhibits a common orientation with a {1 1 1} plane of the grains parallel to the film surface. The in-plane orientations of these grains lead to a general orientation relationship with respect to the YSZ layer: 〈1 1 2̄〉_MgO∥〈1 0 0〉_YSZ, 〈1̄ 1 0〉_MgO∥〈0 1 0〉_YSZ. With a cubic-to-cubic orientation relationship, the BaTiO₃ layer shows the same grain morphology as the MgO layer. These crystallographic relations between the different layers are discussed considering the lattice match and atomic environments across the interfaces.