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Compared with destructive techniques, e.g. three-dimensional electron backscatter diffraction (3D EBSD), [5] with which the sample is serially sectioned and imaged, 3DXRD and similar X-ray nondestructive techniques have the following advantages: They require less sample preparation, thus limiting the introduction of new structures in the sample.
Diffraction from a large three-dimensional periodic structure such as many thousands of atoms in a crystal is called Bragg diffraction. It is similar to what occurs when waves are scattered from a diffraction grating. Bragg diffraction is a consequence of interference between waves reflecting from many different crystal planes.
A blazed diffraction grating reflecting only the green portion of the spectrum from a room's fluorescent lighting. For a diffraction grating, the relationship between the grating spacing (i.e., the distance between adjacent grating grooves or slits), the angle of the wave (light) incidence to the grating, and the diffracted wave from the grating is known as the grating equation.
The recorded series of two-dimensional diffraction patterns, each corresponding to a different crystal orientation, is converted into a three-dimensional set. Data processing begins with indexing the reflections. This means identifying the dimensions of the unit cell and which image peak corresponds to which position in reciprocal space.
The X-ray diffraction patterns of aperiodic crystals contain two sets of peaks, which include "main reflections" and "satellite reflections". [1] Main reflections are usually stronger in intensity and span a lattice defined by three-dimensional reciprocal lattice vectors (,,). Satellite reflections are weaker in intensity and are known as ...
[35] [36] More complete analyses were the demonstration that classical inversion methods could be used for surfaces in 1997 by Dorset and Laurence D. Marks, and in 1998 the work by Jon Gjønnes who combined three-dimensional electron diffraction with precession electron diffraction and direct methods to solve an intermetallic, also using ...
Holography is distinct from specular holography which is a technique for making three-dimensional images by controlling the motion of specularities on a two-dimensional surface. [71] It works by reflectively or refractively manipulating bundles of light rays, not by using interference and diffraction.
If the distance to each source is an integer plus one half of a wavelength, there will be complete destructive interference. Usually, it is sufficient to determine these minima and maxima to explain the observed diffraction effects. The simplest descriptions of diffraction are those in which the situation can be reduced to a two-dimensional ...