X-ray Diffraction (XRD)

X-ray diffraction is a commonly used technique for structural characterisation of materials. Diffraction from single crystals is covered in our crystallography section. Here we concentrate on applications to polycrystalline materials (powders) or alternative sample geometries (e.g. surfaces). Technical information about Diamond’s X-ray diffraction facilities is summarised below.

Even though X-ray sources are widely available in home laboratories, the synchrotron provides a unique environment and unmatched features. Users benefit from a significant increase in data quality and often the synchrotron can solve the structure of otherwise intractable samples.

• wide variety of sample types and geometries including bulk samples, powders and thin film samples, ranging from an engineering component through to a coating;
• adjustable beam sizes help to tailor the experiment by focusing on the best diffracting part of the crystal or improving the signal to noise ratio;
• high photon flux is invaluable for data collection from weakly diffracting, very small or very large samples;
• the latest detector technologies and cutting edge robotics offer a rapid and reliable system for collecting high resolution and good quality data from a large number of crystals or from complex geometries;
• fast measurements allow in situ experiments covering a wide range of different environments;
• the energy tuneable beams allow users to apply anomalous scattering methods.

Types of samples which can be studied range from simple powders which can be loaded in glass capillaries through to large engineered components such as fan blades from aero-engines. 

Applications are multitude and include: 

• Phase identification of crystalline materials
• Polymorphism studies of drug candidate materials (or other organic compounds such as pigments)
• Quantification of strain in engineered components
• Depth profiling of multilayered materials
• Structural characterisation of catalysts under in situ conditions
• High pressure studies using diamond anvil cells
• Phase identification from surfaces