Figure 2
Mapping lattice bending close to the interface.
(a–d), Projections of the 3D RSM onto the (Qx,Qy) plane recorded at different (x,y) positions shown in the insets at the lower left. The arrows indicate the local maxima stemming from diffraction at lattice planes of adjacent crystals with opposite tilt. (e), Close-up view of the RSM projection area in (c) outlined by a dashed rectangle, rotated anticlockwise by 90°. The inset reveals how lattice bending of 1.2-μm-tall adjacent Ge crystals may give rise to multiple peaks in the RSM. Due to the tilted crystal planes in opposite directions at the trench between two adjacent crystals, the Bragg condition is fulfilled for two scattering vectors, Q′ and Q”. K0′ and K0” are the corresponding vectors of the incidence beam, whereas Ks′ and Ks” are the vectors of the exit beam. The lattice bending displayed by series of curved black lines was extracted from the rotation tensor obtained from FEM calculations. The colour maps represent cross-sections through the xz component of the 3D rotation tensor sliced through the middle of the Ge crystals (y = 0). The thick dashed black lines represent the experimental curvatures obtained from synchrotron nanodiffraction experiments. The position of the experimental curvature along the z-axis was chosen such that it matches the curvature calculated by FEM. The scale of the lattice bending was increased by a factor of 200 to make it better visible.
