Figure 14
Simulated powder method. Transmission photography using fixed wavelength (a), (c), (d) and structure factor
S(q) (b), (d), (f) of polycrystalline SC (a), (b), b.c.c. (c), (d) and f.c.c. (e), (f) samples. Miller indices
(hkl) are labeled next to each signal peak. The photograph is produced by randomly rotating a single-crystalline sample in three dimensions and taking the average of over 5000 orientations. The small concentric circular pattern at the center of each photograph is due to Fraunhofer diffraction from the small simulation box, effectively a circular obstacle, after random rotatation. Three methods are used to compute
S(q): with s on a cubic lattice (green vertical lines), with s on spheres (blue dotted line) and Debye's scattering equation (red solid line). |