A method by which one can determine the structure, atomic
arrangement, purity, and identity of unknown crystaline substances.
An X-ray Diffractometer consists of the following components:
1. x-ray tube: consists of a metal casing, a tungsten filament, copper plate, cooling devices, and up to 4 focal points for the x-ray beam.
2. target: stand upon which your unknown (or known) substance is placed
3. detector: like a camera for x rays. It records the patterns of the x-ray "diffraction" or reflections off the substance's surface.
4. Lead casing: umm, keeps out radiation, duh!
The tungsten fillament
is supplied with a current. When the filament is excited
it gives off heat. This heat excites the copper target into giving off electrons
(x rays). A cooling device is present so that the copper
target does not melt. These x-rays are in turn projected
through the focus
point of the x-ray tube towards the studied substance. The atoms absorb
x-rays and emit
them in all directions. Interference
of these waves cancel each other out, except at the diffraction angle. The waves
at those angles are read by the detector. The x-ray tube is then rotated around the subject so that a reading may be taken from multiple angle
s (denoted as 2θ). The readings from the reciever are then (finally) transposed into a readable graph
by PC software (ie JADE).