Neutron powder diffraction

Neutron powder diffraction is complementary technique to the X-ray powder diffraction. It permits to determine crystal and/or magnetic structure of powder or polycrystalline materials, analyse their phase composition, study phase transitions in-situ, etc.

Neutron based studies permits the determination of the structural details and dynamics of atomis arrangements in materials from simple measurements of scattering processes. Neutrons are scattered by nuclei, are sensitive to the atomic magnetic moments, and have scattering and absorption cross-sections independent of atomic number and mass. From this description one can extract advantages of using the neutrons as a solid matter probe.

Here are some of the advantages for using the neutron diffraction technique:

  • deep sample penetration - study of the changes taking place in the volume of the sample not just on the surface; possible to use closed sample environments
  • see the light elements - neutrons can "see" the light elements as a hydrogen (deuterium) or oxygen; some of the elements have negative scattering length -> distinguishing elements standing beside in the periodic table
  • direct interaction with magnetic structure - observation of the magnetic reflections -> study of the magnetic structure

As happened in the life some advantages can be also disadvantages. Deep sample penetration is one of this double-edge sword property. Due to this one need large sample volume for neutrons can scatter from.

Here are some disadvantages when you work with the neutron diffraction:

  • large sample needed - one of the biggest disadvantage; for the good experiment we need the sample volume of few (2-3) cc
  • small neutron flux - the reactor provide small neutron flux so the collecting time can be long

Powder diffractometer MEREDIT available in the Neutron Physics Laboratory

In the Neutron Physical Laboratory there is available neutron powder diffraction instrument called MEREDIT which is open for the scientist across the research fields. If you think that you have some interesting sample and advantages of the neutron diffraction is what you looking for please do not hesitate to contact the instrument responsible.