X-ray diffraction (XRD) helps in phase identification by comparing the diffraction pattern of a sample with known reference patterns of different compounds. Here’s how it works simply:
- When X-rays hit a crystalline sample, they produce a unique set of diffraction peaks depending on the arrangement of atoms in the crystal.
- Each phase (or crystal form) of a compound has its own “fingerprint” pattern of peaks.
- By matching the sample’s peak positions and intensities with reference patterns from databases (like the Powder Diffraction File, PDF), we can identify which phases are present in the sample.
- This allows detection of single or multiple phases, which is useful for checking purity, detecting impurities, or analyzing mixtures.
In short, XRD acts like a fingerprint scanner for crystals, letting us identify the exact phase or combination of phases in a material.