X-Ray Diffraction

X-ray diffraction (XRD) is based on the interference effect from the scattered radiation by the different locations of atoms in the matter (so called “Bragg's Law”).  The x-ray diffraction method is one of the key techniques for the investigation of structural properties of various materials.
In MCPF, the X-Ray Diffraction Laboratory has four x-ray diffraction systems for different purposes of the research and development in the field of materials science.

Instrumentation:

  Laue x-ray diffraction camera
  Powder x-ray diffractometer
  Exchangeable low resolution (parallel beam optics)/high resolution (four crystal monochromator) x-ray diffractometer
  Four circle single crystal x-ray diffractometer

Information Provided from XRD for Single Crystal, Polycrystalline or Layered Materials: 

  Crystal orientation and structural quality
  Structure type and unit cell parameters
  Phase identification
  Grain size determination
  Degree of the crystallinity in a mixture of amorphous and crystalline substance
  Limitation of solubility in a substitutional solid solution
  Layer thickness and interface information of layered materials or superlattices
  Lattice strain, thickness and composition of hetero-epitaxial semiconductor layers
  Dynamic simulation of high resolution rocking curves
  Residual stress analysis
  Total reflectivity by x-ray
  Miller indices and stereographic projection of Laue diffraction pattern
  Three dimensional atomic arrangement of a crystal by means of bond length and angles
  Real time structural thermal behaviour (lattice constant variation with temperature and phase transition) of a single crystal

Typical Applications: 

  Study of structural properties of all kinds of polycrystalline materials
  Study of growth conditions, preferred orientation and crystal quality of various thin films such as metallic, semiconducting, dielectric, piezoelectric, magnetic, non-linear optic, optoelectronic, polymeride films
  Structural characterisation of laboratory-synthesised metal-organic or complex organic compounds: chemical formula, crystal system, space group, unit cell dimension, formula weight, density and absorption coefficient
  Layer structure, lattice mismatch and strain, layer thickness and composition of multiple quantum well semiconductors, superlattices or multilayers
  Crystallinity of polymers under the different processes
  Phase identification of oxides/nitrides (e.g. Ti-O, Fe-O, Al-N, Fe-N)
  Catalyst analysis
  Composition analysis for chemical reaction products (e.g. products on the battery electrodes), or in a mixture (such as cement, clay, etc.)
  Determination of the mis-cut angle of a single crystal

Last updated on 20/01/2005