Grazing Incidence of Diffraction (GID)
The Grazing Incidence of Diffraction (GID) method allows the phase composition of a fabricated material to be probed with depth from a surface of reference.
Irradiation of a sample, with an incident beam which is parallel and at a very low angle to the surface creates diffraction from the crystallites concentrated towards the surface. The depth of x-ray penetration is correlated to the incident angle toward the surface; typical depth data can range from ~20 nanometres to approximately 10 microns. In preparation, the surface of a material must be polished flat to ensure meaningful results.
- Changes in crystal forms deposited on top of a substrate, i.e. TiO2 forms (rutile or anatase) deposited on top of a substrate
- Crystallite size of gold sputtered layers on a substrate
- Oxidation layers at the surface of metallic materials, i.e. MoOx towards the surface of molybdenum metal
- Crystalline oxidised phases towards the surface interface of metal substrates
- Materials where it is suspected that there is a dichotomy between the bulk and the surface
- Layers deposited on a substrate.
Typical Industries using XRD
- Glass, Ceramics and Refractories
- Medical Devices
Grazing Incidence of Diffraction - At a Glance
- Information: Chemical composition, crystalline phase, crystallite size and doping content
- Sample Size: Usually > 100 microns thick with a flat surface area of 20 x 20 mm
- Detection Limits: ~0.5 wt%
- Area Analysed: Dependent upon incident angle
- Data Output: Diffraction traces, phase tables and depth profiles