In order to collect diffraction data from a sample, representative material is
prepared as finely ground material and then presented to the X-ray beam in such a
way that individual crystallites are randomly orientated. The resultant diffraction
trace, as a plot of intensity against “d ” spacing or against 2u value, can be compared
to traces of known material or published standard reference profiles
enabling identification to be made. The International Centre for Diffraction
Data (www.icdd.com) publishes reference patterns on an annual basis. Sophisticated
search–match software to combine diffraction peak positions with chemical
constraints for the system under examination can be employed.