The composition of the diffraction pattern is mainly the position and intensity of the diffraction peak, and our analysis of the XRD pattern is based on the changes in the intensity and position to explain the changes in the micro and macro of the material.
Each material has its own characteristic diffraction pattern, also known as the characteristic diffraction pattern. The cell size of the material determines the position of the diffraction line, that is, the diffraction peak position we see on the diffraction spectrum, the type of atoms in the cell and their position determine the intensity of the diffraction peak, and the symmetry of the crystal shape determines the number of diffraction peaks.
Diffraction occurs only in crystal, and scattering occurs in non-crystal. And when the crystal surface conforms to Bragg's law, the corresponding diffraction signal will be generated. In the XRD spectrum, each substance has its own characteristic diffraction spectrum, different substances produce different diffraction spectra, in a heterogeneous mixture of substances, the spectrum shown in XRD is a simple superposition of each phase.