(Colour online) Crystalline plane tilt angles (Δθ) measured in a µXRD experiment for a rectangular tunnel junction (Co/Fe3O4 sample, 120 µm × 40 µm) for the Co layer (a, b) and CoFe2O4 layer (c, d). At each lateral position of the X-ray beam on the junction the integrated intensity of the peak (rocking scan) (top panels) and the position of the centre of mass of the peak (bottom panels) are reported. The lateral position is displayed on the horizontal axis with respect to the centre of the junction. The reported error bar represents the angular step used when scanning (typically 0.1–0.2°). The hatched rectangular area is the corresponding width of the junction, as from lithography parameters (120 µm and 40 µm, respectively). The insets show schematically the experimental geometry considered: the diffraction plane (containing the incident and scattered X-ray beam) is perpendicular to the surface of the sample and contains the arrow labelled `X-rays'. The thin line describes the lateral position of the X-ray focused beam on the sample; its curvature schematically illustrates the tilt of the Co(0001) crystalline planes.