![]() ![]() By exploiting range of X-ray energies, Laue diffraction allows for collecting lots of XRD data in a single shot, whereas each diffraction spot is assigned to X-ray energy. von Laue is equally frequently mentioned when referring to X-ray diffraction (XRD) that uses a polychromatic light. For bulk samples, a 3D differential-aperture x-ray microscopy technique has been developed that yields the full diffraction information from each submicron volume element.The famous relations between the scattering vector and the crystals are summarized in “Laue equations”, but Mr. For example, more » 2D x-ray microscopy has been applied in studies of the epitaxial growth of oxide films. For thin samples such as deposited films, 2D structural maps are obtained by step-scanning the area of interest. These new microdiffraction capabilities have enabled both 2D and 3D structural studies of materials on mesoscopic length-scales of tenths-to-hundreds of microns. Laue diffraction patterns scattered from the sample are collected with an area detector and then analyzed to obtain the local crystal structure, lattice orientation, and strain tensor. In this technique, white undulator radiation is focused to submicron diameter using elliptical mirrors. We have developed a scanning, polychromatic x-ray microscopy technique with submicron spatial resolution at the Advanced Photon Source. In general, these spatially-resolved measurements provide important new insights and are valuable as input for theoretical and computer modeling studies of a wide range of material processes. In 3D systems, X-ray microscopy investigations have included in-situ studies of microstructural evolution during thermal grain growth in polycrystalline aluminum. In 2D systems, X-ray microdiffraction studies have revealed the mechanisms for local crystallographic tilting in epitaxial oxide films grown on textured Ni substrates for superconducting applications. In 1D systems, we have mapped the structure and orientation of an individual ZnO nanorod along with the associated Ge catalyst particle used to control the nanocrystal growth. This paper will illustrate the application of polychromatic scanning X-ray microscopy with examples from 1D, 2D and 3D materials systems. These measurements, in turn, yield new insights in several classic fields of materials science. Spatially-resolved X-ray microdiffraction studies are now providing previously unavailable measurements of local microstructures. These X-ray diffraction patterns provide real-space maps of the local lattice structure, crystal orientation, grain morphology, and strain tensor. In white-beam mode, a CCD detector records a complete Laue diffraction pattern, which is analyzed more » with an automated indexing program. Publication Date: Research Org.: Lawrence Berkeley National Laboratory (LBNL), Berkeley, CA (United States) Sponsoring Org.: USDOE Office of Science (SC), Basic Energy Sciences (BES) OSTI Identifier: 1379389 Grant/Contract Number: AC02-05CH11231 Resource Type: Accepted Manuscript Journal Name: MRS Bulletin Additional Journal Information: Journal Volume: 41 Journal Issue: 06 Journal ID: ISSN 0883-7694 Publisher: Materials Research Society Country of Publication: United States Language: English Subject: 36 MATERIALS SCIENCE x-ray diffraction crystallographic structure phase = 500 nm FWHM are now routine, and 90 nm focus has been demonstrated. ![]() National Synchrotron Radiation Research Center (Taiwan).Department of Materials Science and Engineering and Advanced Materials Processing and Analysis Center of Central Florida, Orlando, FL (United States). Department of Mechanical and Aerospace Engineering Hong Kong University of Science and Technology (China).Lastly, we extrapolate how the technique is anticipated to evolve in the near future and its potential emerging applications at a free-electron laser facility. Fast data collection provided by state-of-the-art area detectors and fully automated pattern indexing algorithms optimized for speed make it possible to map large portions of a sample with fine step size and obtain quantitative images of its microstructure in near real time. As synchrotron Laue x-ray microdiffraction enters its 20th year of existence and new synchrotron nanoprobe facilities are being built and commissioned around the world, we take the opportunity to overview current capabilities as well as the latest technical developments. This technique, employed at a synchrotron facility, is particularly suitable for fast mapping the mechanical and microstructural properties of inhomogeneous multiphase polycrystalline samples, as well as imperfect epitaxial films or crystals. We present that local crystal structure, crystal orientation, and crystal deformation can all be probed by Laue diffraction using a submicron x-ray beam. ![]()
0 Comments
Leave a Reply. |