ABSTRACT
It is really remarkable that an analytical method with its roots in the 1930s and earlier is still one of the most useful of all methods in use today, but it is true. Perhaps the only methods that can provide equivalent important information about crystalline materials are elemental chemical analysis and the optical microscope. Of all the spectroscopies, which include infrared, visible, Raman, ultraviolet, etc., X-ray diffraction (XRD) is the only one where all the members of the data set may be related to every other member through fundamental equations. The relationships allow the use ofthe data to prove many points with considerable
confidence including phase purity and the properties ofthe crystal structure. Not only is the XRD method still in use, but XRD is still advancing rapidly in the types of problems it can attack and the accuracies that may be achieved.
