Two-dimensional powder diffraction

Two-dimensional X-ray diffraction, also referred to as 2D powder diffraction, covers X-ray diffraction applications with a 2D detector and corresponding data reduction and analysis. A two-dimensional diffraction pattern contains abundant information about the atomic arrangement, microstructure and defects of a solid or liquid material. In recent years, use of two-dimensional detectors has dramatically increased in academic research and various industries. When a 2D detector is used for X-ray powder diffraction, the diffraction cones are intercepted by the area detector and the X-ray intensity distribution on the sensing area is converted to a 2D diffraction pattern. A 2D diffraction pattern contains far more information than a conventional diffraction pattern, and therefore demands a special data-collection strategy and data-evaluation algorithms. This chapter covers the basic concepts and recent progress in two-dimensional X-ray diffraction theory and technologies, including geometry conventions, X-ray source and optics, two-dimensional detectors, and diffraction-data interpretation, and various applications, such as phase identification, texture, stress, crystallinity and crystallite-size analysis.