X-ray powder diffraction---or XRD---is used to measure crystalline compounds and
provides a quantitative and qualitative analysis of compounds that cannot be measured
by other means. By shooting an X-Ray at a compound, XRD can measure the diffraction
of the beam from different sections of the compound. This measurement can then be
used to understand the composition of the compound on an atomic level, since all
compounds diffract the beam differently. XRD measurements show structural make-up,
content and size of crystalline structures.
7. X-ray tube or Coolidge tube
• Most common source
• Berrylium window
• Poor output efficiency (5%)
8. Production of X-rays using
• Certain radioactive substances
produce X-rays as a result of their
radioactive decay process.
9. Wavelength selector
◦ thin metallic strips of definite thickness eg. Zirconium filter
◦ these are crystals which can diffract X-rays according to their wavelength.
10. A crystal monochromator
• A useful wavelength range from a
crystal is determined by its lattice
• Crystal is placed on a rotating table
or a goniometer
• Works on the principle of Bragg’s
• Rays of different wavelengths can
be collected by varying angle θ.
11. Sample holder
It is a rotating table called as crystal mount
Sample is placed at the centre of a crystal mount, which is kept rotating
at a particular speed.