Debye-Scherrer diagram

Within the separated liquid phases, Si02 and Al203 were analyzed according to conventional chemical methods. Na20 was determined by flame photometry. Crystalline reaction products were identified by Debye-Scherrer diagrams the composition of the mixtures was determined by comparison with diagrams of test samples. 

If a high number of small crystals are used as a target and the incident radiation is monochromatic, Ewald s condition will be satisfied in a certain fraction of these cr als and, because of the rotational symmetry of the construction about PO, the diffraction pattern will consist of rings centered on the incident beam. This is the Debye-Scherrer diagram. 

A Debye-Scherrer diagram of La2Se3 is given, Guittard etal. [7], also see Flahaut etal. [3], Suchet et al. [12], Lashkarev, Paderno [25], Lashkarev et al. [28], Miller etal. [26], Benacerraf, Guittard [8]. Additional data for the lattice constants for M2Se3 are summarized in the following table ... 

The deformation of the lattice as a result of the mechanical working is seen from the broadening of the lines in the X-ray diffraction picture, which are narrow under normal circumstances (Debye-Scherrer or powder diagram). 

Schematic diagram of a sealed laboratory X ray tube with key components indicated (left), and a photograph of a tube (right). In modern tubes the clear glass vacuum housing has been substituted by ceramic. Manufactur ers provide various dimensions for the W filament, leading to broad , normal , fine and long fine focus tubes. The X rays emerge from the four circular Be windows in the base, two of which are parallel to the filament, providing a line source of X rays, and two of which are perpendicular, providing a point source . A line source from a fine or long fine focus tube is preferred for a modern powder diffractometer. Historically, point sources were used for Debye Scherrer cameras.

Although different orientations of crystalline or smectic domains can be produced by different alignment procedures, the packing within the domains is the same. This is also valid for a sample with random orientation of domains for which the reflections on a Debye-Scherrer x-ray diagram exhibit the same spacings as observed for oriented samples. 

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