Microstructure of BaRuO_(3) thin films grown on (001) SrTiO_(3)

摘要

BaRuO_(3) thin films with hexagonal 4H structure were grown on (001) SrTiO_(3) by a 90°off-axis rf-sputtering technique. The thin films were epitaxially grown on the (001) surface of SrTiO_(3), with (2023) planes parallel to the surface of the substrate. Within the growth plane, the film consists of four different crystallographic orientations with respect to the substrate, defined by the surface symmetry of the (001) SrTiO_(3) substrate. BaRuO_(3) grains of all four orientations show an anisotropic shape elongated along the 1210 direction. The reason for the anisotropic growth is that the lattice mismatch between BaRuO_(3) and SrTiO_(3) is smaller along the 1210 direction of SrTiO_(3) in comparison to that along its perpendicular direction. Stacking faults and intergrowths of the 9R structure were observed in small local regions of the film.