Figure 1
XRD measurements for the uncapped CBST film.
(a) The schematic crystal structures of STO, CBST and Te. (b) XRD pattern along the surface normal direction. All of the peak positions correspond to (n n n) of the cubic STO lattice or (0 0 0 3n) of the hexagonal CBST lattice. (Inset) XRD results measured with the same conditions at various time points. Red, black and blue lines are measured after the exposure to x-rays for about 5, 9 and 21.5 hours, respectively. (c,d) Reciprocal space maps in the K-L plane with H = 0. Sharp spots at positions only satisfying the space group of STO or CBST lattice confirm the epitaxial growth of the CBST film. (e) Rocking curves for CBST (0 0 0 21) and (0 1 –1 20) reflections. The width of the (0 1 –1 20) peak is wider than that of (0 0 0 21) indicating better orientational order along the stacking direction. (f) Azimuthal scans of STO {2 2 1} and CBST {0 1 –1 20} reflections in which the azimuthal angle is defined with respect to the [1 1 –2] and [0 1 –1 0] directions on the surface of STO and CBST, respectively. The relation between the azimuthal peak positions indicates an in-plane epitaxial relationship of STO [1 1 –2] || CBST [0 1 –1 0]. (g) θ-Φ map of the (0 1 –1 20) reflection. Two satellite peaks separated by about 4° from the main (0 1 –1 20) peaks are present indicating three crystal domains where the crystallographic axes of the satellite domains are tilted by about ±4°. (h) Schematic diagram of the supercells showing a reasonable lattice match. The different colored spheres represent metal atoms, making no distinction between different kinds of atoms, in different planes with oxygen atoms being ignored. The cell presented by blue rectangles has a size of around 66 × 38 Å2. Green and orange rectangles rotated by 4° from the blue rectangle have (lower left to upper right) diagonal vortices on different colored spheres, i.e., on different planes.
