Fig. 1
The schematics of film systems and CTRs measurement. Schematic of tilt mismatch across CaTiO3 and substrate interfaces for a CaTiO3/DyScO3b CaTiO3/LSAT. The yellow highlighted area represents the abrupt mismatch in in-plane oxygen octahedra tilt angles. c Experimental geometry of synchrotron X-ray diffraction used in the coherent Bragg rods analysis (COBRA) is schematically shown. The diffraction intensities along crystal truncation rods (CTRs) are mapped out by varying their intersect positions with Ewald sphere through rotating the sample about its surface normal. (H, K, L) is the coordinates in reciprocal lattice. d Several examples of measured crystal truncation rods, labeled as (H, K, L), where the intensity versus the reciprocal vector L is shown (blue dots) for CaTiO3/NdGaO3 at room temperature, as well as the corresponding COBRA fits (orange solid lines). The reciprocal units are under 2 × 2 × 2 pseudocubic notation. Note that for COBRA, the substrate Bragg peaks intensities (the trees) are not as important as the diffraction structure between the peaks (the forest floor)
