X-ray diffraction Patterns for different structures:

Single crystal:
A single crystal specimen in a Bragg-Brentano diffractometer would produce only one family of peaks in the diffraction pattern as shown in Figure 3.03.

Figure 3.03: Typical XRD pattern of single crystal specimen.

Powders / Polycrystals:

Powders / polycrystalline samples contain thousands of crystallites with each one having a single crystal structure. However, each of the crystals are oriented randomly (see Figure 3.04). Therefore, all possible diffraction peaks should be observed.

Figure 3.04: Typical XRD pattern of polycrystal specimen.