Surface Structures
Surface features in a material produce variations in the CTR intensity, which can be measured and used to evaluate what surface structures may be present. Two examples of this are shown in Fig. 3. In the case of a miscut at an angle, a second set of rods is produced in reciprocal space called superlattice rods, tilted from the regular lattice rods by the same angle, . The X-ray intensity is strongest in the region of intersection between the lattice rods (grey bars) and superlattice rods (black lines). In the case of ordered alternating steps, the CTR intensity is chopped into segments, as shown. In real materials, the occurrence of surface features will rarely be so regular, but these two examples show the way in which surface miscuts and roughness are manifested in the obtained diffraction patterns.
Read more about this topic: X-ray Crystal Truncation Rod
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