Diffraction group (DIF)

The instruments of the Diffraction group (DIF) use neutron diffraction for studying the structure of materials used in everyday life. The latter can be in the form of liquid or amorphous materials, crystalline powders or single crystals. The atomic and/or magnetic structures of metal/alloys, mineral, organic, macromolecular or biological materials can be investigated.

Single crystal diffractometers

Single-crystal diffraction is a powerful method for the investigation of structural details in condensed matter. Hot neutrons are required to uncover the finest details in the nuclear positions and neutron spin polarisation is a handle to separate mixed components (nuclear polarisation, magnetic and electronic scattering). These diffractometers can be used to find:

  • average atomic positions. From these we can learn how the atoms are bound together to form molecules, and how the molecules are stacked
  • local atomic distributions. This gives information about the time averaged thermal motion or the local atomic disorder
  • magnetic structures and magnetic moment distributions. Structural data of this kind are required for a large number of systems, ranging from organic molecules to high temperature superconductors.

Often studies are made as a function of temperature, pressure and magnetic field which may lead to important modifications of the crystal structure.