The theory of X-ray diffraction developed greatly in the early and mid-20 th century to quantify experimental data. Scherrer and Debye showed that since the crystal lattice and experimental setup are a finite size, diffraction may still occur at points surrounding the Lau-Bragg diffraction condition (Eqn. 1), yielding crystallite size. Similarly, microstrain and the defect structure of the material also disrupt the periodic lattice and broaden peaks . In polycrystalline samples, preferential orientation obscures diffraction in the out-of-plane direction. The Lotgering's factor mathematically describes the change in peak intensity according to this preferential orientation.