Applications

The Diffraction User Center offers a unique selection of diffraction-based instruments, radiation sources (x-ray, neutron and synchrotron), and methods for characterization of crystalline materials.

Rapid data collection, coupled with control of temperature and atmosphere, permits in-situ studies and simulation of materials processing. Frequently these in situ studies are undertaken to clarify DSC, TGA, DTA or dilatometer data, such as may be determined through the Thermophysical Properties User Center.

Topics which can be studied with the furnace equipped instruments include:

• Phase transformations
• Order/disorder transformations
• Solid state reactions
• Crystallization kinetics
• Oxidation, reduction and corrosion
• Lattice thermal expansion
• Crystal structure changes

Room temperature diffraction studies possible in the Diffraction User Center include:

• Phase identification
• Quantitative phase analysis
• Crystal structure determination.
• Crystallite size and residual microstrain

Macro and micro residual strain and texture measurements by diffraction methods are available through the Residual Stress User Center utilizing the neutron powder diffractometers, the X14A synchrotron beam line, or four-axis powder-texture-stress x-ray diffractometers.

The recent inclusion of synchrotron X-ray facilities into this User Center has expanded our capabilities to include diffraction from very thin samples, provides a much narrower peak shape and hence higher resolution, increases elemental sensitivity via use of multiple wavelengths near X-ray absorption edges, and permits measurement of data for EXAFS analysis. Reflectometry is also possible.