D8 DISCOVER, X-ray diffraction

Non-Coplanar or “In-Plane” GID Solutions for Soft Matter and Crystalline Materials

Non-Coplanar Lab Report, XRD

Non-coplanar GID (Grazing Incidence Diffraction) emerged in the early 1990s as a technique for investigating the near-surface region of samples (ten or fewer nm beneath the air-sample interface). It exploits the high intensity of the total external reflection condition while simultaneously Bragg-diffracting from planes that are nearly perpendicular to the sample surface. 

Non-coplanar GID is used for determining information in the plane of the sample surface, which is why it is also referred to as “in-plane” diffraction. In particular, lattice parameters, surface-plane relaxation, texture and crystallite size are among the sample information that can be obtained with GID.

Soft matter such as gels, polymers and liquids, single crystals, polycrystalline sheets and powders can be investigated. Particular applications include:

  • Polycrystalline materials: Phase ID and lattice parameters, lateral grain size, in-plane preferred orientation
  • Single crystals: in-plane lattice parameter (high accuracy using the bond method), azimuthal orientation of layers with respect to the substrate, evidence of twinning
  • Soft matter: in-plane size and shape of colloids, distance correlation functions, length scales of in-plane density modulations
  • Any other in-plane applications where standard diffraction geometries fail due to lack of scattered intensity