The difference between powder XRD and single-crystal XRD lies mainly in the type of sample and the kind of information obtained:
- Sample form:
- Powder XRD: The sample is in the form of fine powder, which contains many tiny randomly oriented crystals.
- Single-crystal XRD: The sample is a single, well-formed crystal with a uniform orientation.
- Data collected:
- Powder XRD: Produces a diffraction pattern of peaks that represent all crystal planes. It is mainly used to identify phases, determine lattice parameters, and check purity.
- Single-crystal XRD: Produces a 3D diffraction pattern from the crystal, which can be used to determine the exact 3D arrangement of atoms in the crystal.
- Detail level:
- Powder XRD: Gives average structural information.
- Single-crystal XRD: Gives precise, detailed atomic-level structure.
- Applications:
- Powder XRD: Used for phase identification, quality control, and studying crystal size or strain.
- Single-crystal XRD: Used for determining complex crystal structures, molecular geometry, and atomic positions.
In short: Powder XRD is like looking at a group of crystals together, giving general info, while single-crystal XRD looks at one crystal in detail, giving exact atomic positions.