Laue Methos by X Ray Diffraction-Solid State Physics-Presentation, Slides of Solid State Physics

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 The history of this method is to cover various fundamental problems.

 The Bragg’s equation does not explicitly tell us about the directions in which diffraction occurs.

 Laue equations make the directionality of the process more obvious as we have a set of three equations, one for each crystallographic axis that must be simultaneously satisfied.

 To become familiar with fundamental x-ray diffraction techniques: to learn how to take a Laue photograph and how to analyze the spectrum on the basis of the physical principles of diffraction by crystals.

 X-ray source

 Device to hold and manipulate crystal

 detector

There are two basic technique

 Back-reflection Laue technique

 Transmission Laue technique

 The technique in which the beam reflected back in direction close to that of the incident x-ray beam

 It is especially valuable for determine the orientation of the lattice inside crystals when the crystal are large and therefore opaque to x-ray

In the transmission Laue method, the film is placed behind the crystal to record beams which are transmitted through the crystal.

One side of the cone of Laue reflections is defined by the transmitted beam. The film intersects the cone, with the diffraction spots generally lying on an ellipse.

 Extremely short data collection time-resolved crystallography

 A few exposures covers reciprocal space specially for high symmetry space group

 Reciprocal lattice concept

 Ewald’s sphere concept