For research facilities with access to synchrotron X-ray sources, X-ray absorption microtomography (XMT) has evolved from an experimental imaging method to a specialized, if not yet routine, microscopy for imaging the three-dimensional (3D) distribution of linear attenuation coefficients and, in some cases, elemental concentration with micron spatial resolution. Recent advances in source and detector design have produced conventional X-ray source instruments with comparable spatial resolution but with lower throughput and without element specific imaging. Both classes of instrument produce 3D images for analysis. We discuss an integrated approach for the implementation of analytical XMT to support basic research into the structure-property relationships of a variety of materials. The essential components include instrumentation for collecting quantitative 3D images, a 3D image processing environment to address questions as to the quantity, composition, geometry, and relationships among the features in one or more images, and visualization to provide insight and communicate results. We give examples of image analysis of resolved and unresolved pore spaces of sandstones.

X-ray powder diffraction data for the trigonal form of disilver trihydrogen paraperiodate, Ag2H3IO6, are reported. The cell parameters are a=5.941 89(3), c=12.7253(1) Å, V=389.089(6) Å3, and ρ=5.65 g cm−3 for Z=3. A full-profile Rietveld refinement confirms the monophasic nature of the sample and the presence of two-dimensional corrugated layers of the A2BO6 type linked by hydrogen bonds. Short unsupported Ag–Ag contacts (about 3.02 Å) of the argentophilic type are also shown.

X-ray powder diffraction data for a rhombohedral AlPt phase formed by self-propagating, high-temperature reactions of Al∕Pt bi-layer films are reported. Multilayer Al∕Pt thin film samples, reacted in air or vacuum, transformed into rhombohedral AlPt with space group R-3(148). Indexing and lattice parameter refinement of AlPt powders (generated from thin-film samples) yielded trigonal/hexagonal unit-cell lattice parameters of a=15.623(6) Å and c=5.305(2) Å, Z=39, and V=1121.5 Å3.

X-ray powder diffraction data for N,N'-diphenylguanidinium nitrate, within the temperature range of 103–293 K, are reported. The pattern at 293 K was confirmed by a fitting of the overall parameters performed with FULLPROF using the atomic parameters obtained from single-crystal studies. The compound is orthorhombic, space group Pna21 (33), with unit-cell parameters a=1.7058(4) nm, b=1.3933(3) nm, c=0.5821(1) nm, and V=1.3834(6) nm3. The unit-cell parameters for the other six temperatures measured were determined by performing pattern matching with FULLPROF. The unit-cell volume contracted on cooling from 1.3834(6) nm3 to 1.3403(4) nm3. The thermal expansion tensor was calculated from the changes of the unit-cell parameters with temperature. The elements of the thermal expansion tensor at 293 K are α11=125(4),α22=57(9), and α33=82(3)×10−6 K−1.

X-ray imaging techniques based on Compton backscatter permit inspection and screening of sea containers, a wide variety of vehicles, luggage, and even people. In contrast to more commonly used transmission images, backscatter imaging involves positioning both source and detection apparatus on only one side of a target object. This presents the user with inspection opportunities in situations that may be extremely difficult, if not impossible, for transmission systems that require access by the detector subsystem to the opposing side of the target. The backscatter image is somewhat akin to a photograph of the contents of a closed container, taken through the container walls. Techniques for producing X-ray images based on Compton scattering will be discussed, along with wide-ranging examples of how systems based on these principles are used to perform inspections for both security applications and for the detection of contraband materials at ports and borders. Potential applications in the area of nondestructive evaluation will also be considered. Differences in the type of information displayed by transmission and backscatter images will be highlighted, and tradeoffs between backscatter image quality and interpretability, scan speed, effective penetration, and X-ray tube voltage will also be discussed. The method used in scanning the target object results in an extremely low radiation dose, a result that significantly broadens the application spectrum for this imaging technique.

The indexed powder diffraction pattern and related crystallographic data for polymorphic form 2 of carnidazole (C8H12N4O3S) are reported, as a first step in the structure determination by powder diffraction methods. The unit cell dimensions were determined from high resolution synchrotron powder diffraction data (λ=0.079 998 0 nm) and evaluated by indexing programs. The monoclinic cell found for this polymorph is a=1.3908(2) nm, b=08094(2) nm, c=1.0645(2) nm, β=110.82(2)°,V=1.12015(27)nm3, Z=4, Dx=1.445 Mg∕m3.

An experimental X-ray powder diffraction pattern was produced and analyzed for alpha-polymorphic tegafur, also called Ftorafur (an antineoplastic agent). The indexed data matched the powder patterns in the ICDD PDF-4/Organics database calculated from the reported single-crystal X-ray diffraction data in the Cambridge Structural Database. Alpha tegafur has a triclinic crystal system, with reduced cell parameters of a=16.720(6) Å, b=9.021(5) Å, c=5.995(3) Å, α=93.66(4)°, β=93.15(8)°, γ=100.14(4)°. There are four formula units contained in one unit cell. The cell volume and space group were determined to be 886.27 Å3 and P-1, respectively.

An incident beam X-ray collimator for Mao-Bell type diamond anvil cell (DAC) has been developed. Alignment of the collimator is carried out in situ while viewing the image of the collimated X-ray spot formed on a thin layer of fluorescent material spread on the diamond anvil culets with the help of a microscope. Special precaution has been taken to meet the radiation safety requirements during alignment and routine use. This collimator is of immense help for laboratory based high pressure X-ray diffraction experiments.

Botallackite, Cu2(OH)3Cl, from the Botallack mining area in Cornwall, United Kingdom, has been reinvestigated regarding physical, optical, chemical, and X-ray powder diffraction data. It forms emerald-green tabular crystals slightly elongated along [010] with {001} (dominant), {100}, {010}, and {011}. Botallackite is biaxial positive, 2V=70(2)°, the optical orientation is Y∧c 22(2)° (in obtuse β), Z=b. Electron-microprobe analyses gave CuO 73.26, ZnO 0.22, Cl 16.80, H2O (calc) 12.37, total 102.65, less O=Cl 3.79, total 98.86 wt %, corresponding to the empirical formula Cu1.99Zn0.01(OH)2.97Cl1.03 (based on four anions). Unit cell parameters refined from X-ray powder diffraction data are a 5.7155(5), b 6.1255(6), c 5.6336(4) Å, β 93.090(8), V 196.95(2)Å3,Z=2.

A simple method is described that uses a KCl powder sample and a digital camera to monitor the size, location, and inhomogeneity of the incident X-ray beam in a powder diffractometer. The method has been used successfully to detect problems in the sample holder and the divergence slit of a powder diffractometer used in our laboratory.

Numerous methods are available to forensic scientists for detecting fingerprints in which the prints are treated with various agents to enhance the visual contrast between the print and the surface. In the present work, the spatial elemental imaging capabilities of micro-X-ray fluorescence (MXRF) were used to visualize fingerprint patterns based on inorganic elements present in the prints. A major advantage of using MXRF is that the prints are left unaltered for other analyses, such as deoxyribonucleic acid extraction or for archiving. Most of the fingerprints which were examined were imaged from the potassium and chlorine present in the print residue. Among the various prints studied, lower count rates were also observed in the elemental maps of Ca, Al, Na, Mg, Si, P, S, and the X-ray source scatter. A sebaceous oily fingerprint left by one subject was successfully imaged by MXRF, but sebaceous prints left by a different person were undetectable, indicating that print elemental composition may be person and/or diet dependent. Prints containing substances that might be found in real-world cases were also visualized including sweat, lotion, saliva, and sunscreen.

Thin-walled heat-shrink poly(ethylene terephthalate) (PET) tubing is reported for use as an alternative for glass and Kapton® capillaries. PET tubing displays properties such as low X-ray absorption and smooth diffraction profiles. The 2.0 mm thin-walled (0.05 mm thick) and 0.5 mm thin-walled (0.02 mm thick) heat-shrink PET capillaries are 86% and 96% transparent to 1.54 Å X-rays. The low X-ray absorption and relatively smooth X-ray scattering profile of PET make it an ideal material for the home laboratory where the long wavelength, low flux, and low brilliance X-ray sources are employed. PET capillaries can be easily cut and manipulated and fixed to copper pins, which in turn can be employed in low-temperature and automated data collection routines.

An electron probe X-ray microanalysis (EPMA) technique using an energy-dispersive X-ray detector with an ultrathin window, designated low-Z particle EPM, has been developed. The low-Z particle EPMA allows the quantitative determination of concentrations of low-Z elements, such as C, N, and O, as well as higher-Z elements that can be analyzed by conventional energy-dispersive EPMA. The quantitative determination of low-Z elements (using full Monte Carlo simulations, from the electron impact to the X-ray detection) in individual environmental particles has improved the applicability of single-particle analysis, especially in atmospheric environmental aerosol research; many environmentally important atmospheric particles, e.g. sulfates, nitrates, ammonium, and carbonaceous particles, contain low-Z elements. The low-Z particle EPMA was applied to characterize loess soil particle samples of which the chemical compositions are well defined by the use of various bulk analytical methods. Chemical compositions of the loess samples obtained from the low-Z particle EPMA turn out to be close to those from bulk analyses. In addition, it is demonstrated that the technique can also be used to assess the heterogeneity of individual particles.

A new polymorph of Al2(WO4)3 is observed from in situ high pressure powder X-ray diffraction (ADXRD) measurements at 3.4 GPa. The ADXRD pattern at 3.4 GPa could be explained based on a monoclinic lattice (space group P21) with unit cell parameters: a=9.5884(24), b=12.5204(38), c=7.8463(33) Å, and β=91.98(2)°.

The definitions for important Rietveld error indices are defined and discussed. It is shown that while smaller error index values indicate a better fit of a model to the data, wrong models with poor quality data may exhibit smaller values error index values than some superb models with very high quality data.

The versatility of confocal micro X-ray fluorescence (MXRF) in analyzing thin films on semiconductor wafers is demonstrated. Unlike conventional MXRF, confocal MXRF can depth profile sample layers and reduce spectral background. Nondestructive quantification of the silicon dioxide concentration in hafnium silicate thin films is an example of one application demonstrating the advantage of confocal MXRF. Additionally, the growth of titanium nitride films on various high-k gate dielectric substrates was analyzed with confocal MXRF due to its ability to detect sub-nm film thickness changes.