Lattice monoclinization of YBa2Cu3O7−x films

Abstract Epitaxial YBa 2 Cu 3 O 7- x films grown on (001) SrTiO 3 substrates or (001) r (in morphological rhomphological rhombohedral notations ) Li-NbO 3 substrates were investigated by X-ray diffractometry. It was established that in the case of small interface misfit between the film and the substrate, the film cell had a monoclinic deformation with the b -axis shifting by 0.3–0.5δ from an orthogonal Angle. A misorientation of the (001) SrTiO 3 growth surface several degrees in the [110] direction or using a pseudo cubic (001) r slice of LiNbO 3 promoted the prevailing development of (110) twin boundaries in the films.