A specimen containing nanograms of sulfur, calcium, and 3d transition metal elements was measured by incident X-ray beams of various sizes restricted by a waveguide placed in a portable TXRF spectrometer. The signal to background ratios of spectra decreased with an increase in incident X-ray beam size. The portable spectrometer was also applied to rainwater and a specimen containing antimony and rare earth elements. Nanograms of elements in these specimens were detected by K-line or L-line excitation.

Isothermal sections at 1100 and 1500 °C were determined by X-ray powder diffraction method to reveal stable phases and chemical pathways in the Co–Si–C system. There is no ternary compound present in either isothermal. Cobalt silicides are formed in the Co-rich region at temperatures lower than those in the Si-rich region. CoSi2 reacts with carbon to form CoSi and SiC at 1500 °C, and Co2Si and CoSi are more stable in equilibrium with carbon. The results are also discussed in terms of thermodynamics and binding energy of the reacting substances.

The two-dimensional XRD (GADDS) was used to characterize the microstructure of an applied self-leveling compound (SLC). A calcium aluminate cement based SLC was prepared on two different substrates (water absorbent and nonwater absorbent) to determine the vertical distribution of the crystalline phases. The application of the GADDS enables the detection of the phase composition of the hydrating mortar in horizontal slices. Thus the analysis could be carried out in position-sensitive mode at three different areas: near the bottom, in the center, and at the top of the mortar. For investigation of SLCs from the very early hydration stage up to 10 h of hydration, a custom-made in situ sample holder for the measurements was designed and constructed. The combination of the GADDS and the custom-made in situ sample holder provides the possibility to characterize additionally the time-dependent phase composition within the SLC. The nonabsorbent substrate has no effect on the hydration of the binder phases but the absorbent substrate influences the formation of ettringite. In the top layer of the SLC the ettringite content is reduced during the first hours of hydration. The absorbing forces of the substrate lead to migration of the mix water to the substrate. This lack of water results in the reduced formation of ettringite.

The crystal structure of titanium-tin tellurium oxide Sn0.59Ti0.41Te3O8 has been determined using X-ray powder diffraction techniques. At room temperature, the title compound crystallizes in cubic space group Ia-3, with lattice parameter a=11.05515(6) Å. Rietveld refinement of the structure led to final confidence factors Rp=0.0395 and Rwp=0.0577. The structure of Sn0.59Ti0.41Te3O8 consists of isolated Ti/SnO6-octahedra slightly deformed in the a direction. The TeO4E [E=lone pair of Te(IV) atoms] groups are located between the octahedra ensuring the stability of the structure by Ti/Sn-O-Te bonding contacts. Only one peak in thermal behavior was detected for this compound at 488 K by differential scanning calorimetry experiment. An IR spectroscopic study is employed as a means to obtain preliminary structural information and shows the presence of the Ti/SnO6 and TeO4E groups. This result is later confirmed by X-ray diffraction studies.

Verification of materials is an increasingly important need in pharmaceutical distribution. XStream Systems, Inc. has developed an energy dispersive X-ray diffraction (EDXRD) system which can quickly verify crystalline pharmaceuticals in the distribution cycle. Materials may be in solid or powder form and the technique is nondestructive. Unlike angular X-ray diffraction (AXRD), a “white” X-ray beam between 20 and 80 keV is used. This energetic beam can penetrate through relatively thick materials, diffracting from crystallites within the samples. Materials can be observed even when they are located within opaque, sealed containers. That is, for most cases the drugs can be examined in their sealed, packaged vials without any sample preparation. The tabletop unit uses a confocal geometry to maximize the X-ray intensity from a relatively low-powered, air-cooled X-ray source. The beam is collimated by a circular slit assembly before the sample. A similar slit assembly after the sample collimates the diffracted beam. A single, state-of-the-art, CdTe solid-state detector with a multichannel analyzer is used to process the diffracted signal. This collimation system interrogates a doughnut-shaped volume within the sample under test. One of the design goals was to develop a unit that is capable of performing quick verification or detection of complex materials and mixtures at a number of points along the distribution paths yet can be operated by personnel with minimal scientific knowledge. Rapid identification of unknowns is possible using neural network search algorithms or pattern matching techniques. The Material Recognition Software Engine (MRSE) utilizes a localized SQL database to store and process the raw spectra data. The MRSE takes the sample data and determines if it matches any known patterns within its database. This engine has demonstrated that it can verify a number of drugs within 30 s with better than 97% accuracy.

Powder X-ray diffraction studies of a lithium salt of thiazolidine-4-carboxylic acid (Li-TC4) of composition LiC4H6NSO2 are presented in this paper. Analysis of the synchrotron powder X-ray diffraction data showed that the complex has an orthorhombic symmetry with space group P212121. Unit cell parameters after the refinement using the Pawley method are: a=19.4931(3) Å, b=4.947 77(6) Å, c=6.201 64(8) Å, and V=598.051 Å3.

ZnSe-based heterostructures grown on GaAs substrates have been investigated for use in pin-diode LED applications. In this study, a conventional Bragg-Brentano diffractometer (BBD) has been used to screen samples for phase identification, crystallite size, presence of polycrystalline ZnSe, and initial rocking curve (RC) analysis. A limitation of the conventional diffractometer is that the smallest RC full width at half maximum (FWHM) that can be achieved is 500 to 600 arc sec. As deposition parameters are optimized and the RC limit of the conventional diffractometer is reached, analysis is moved to a four-bounce high-resolution diffractometer (HRD). Although more time for analysis is required, using the HRD has a RC resolution advantage, where RCs of <20 arc sec are obtained for neat GaAs wafers. Combining the BBD and HRD instruments for analysis of ZnSe films grown on GaAs substrates allows for an efficient means of high sample throughput combined with an accurate measurement of film alignment.

The electrochemical reaction behavior of a commercial Li-ion battery (LiFePO4-based cathode, graphite-based anode) has been measured via in situ neutron diffraction. A multivariate analysis was successfully applied to the neutron diffraction data set facilitating in the determination of Li bearing phases participating in the electrochemical reaction in both the anode and cathode as a function of state-of-charge (SOC). The analysis resulted in quantified phase fraction values for LiFePO4 and FePO4 cathode compounds as well as the identification of staging behavior of Li6, Li12, Li24, and graphite phases in the anode. An additional Li-graphite phase has also been tentatively identified during electrochemical cycling as LiC48 at conditions of ∼5% to 15% SOC.

A single-pulse X-ray diffraction (XRD) diagnostic has been developed for the investigation of shocked material properties on a very short time scale. The diagnostic, which consists of a 37-stage Marx bank high-voltage pulse generator coupled to a needle-and-washer electron beam diode via coaxial cable, produces line-and-bremsstrahlung X-ray emission in a 40 ns pulse. The molybdenum anode produces 0.71 Å characteristic Kα lines used for diffraction. The X-ray beam passes through a pinhole collimator and is incident on the sample with an approximately 2 mm×5 mm spot and 1° full width at half maximum angular divergence. Coherent scattering from the sample produces a Debye-Scherrer diffraction pattern on an image plate located at 75 mm from the polycrystalline sample surface. An experimental study of the polycrystalline structures of zirconium and tin under high-pressure shock loading has been conducted with single-pulse XRD. The experimental targets were 0.1-mm-thick foils of zirconium and tin using 0.4-mm-thick vitreous carbon back windows for shock loading, and the shocks were produced by either Detasheet or PBX-9501 high explosives buffered by 1-mm-thick 6061-T6 aluminum. The diffraction patterns from both shocked zirconium and tin indicated a phase transition into a polymorphic mix of amorphous and new solid phases.

Results from Monte Carlo simulations of two-dimensional projections for a simple real sample (an aluminium cube with a cylindrical hole filled by air or steel) in a realistic experimental environment are presented. A meaningful comparison with measurements was therefore possible. Coherent and incoherent scattering as well as excitation of fluorescent radiation are accounted for; multiple sequences of these interactions are followed up to a selectable order. Such simulations are important aids to modern metrological applications of computed tomography where the dimensional accuracy of hidden or inaccessible components of work pieces is determined. The complex process requires a high level of optimization of the instrumental parameters for each sample type whereby the accurate simulation of the physical interactions between X-rays and the sample material is a supplement and alternative to time consuming measurements.

The development of a tool called the Service Load Factor (SLF) for railway tapered roller bearings using residual stress and retained austenite data is presented. Case-carburized tapered roller bearings used in the railroad industry are manufactured with a dual-phase microstructure that consists primarily of tempered martensite and retained austenite. The retained austenite phase is metastable, and will transform to martensite with sufficient thermal or mechanical energy during service. The increase in surface volume because of transformation, and the subsequent increase in compressive residual stress could indicate the onset of certain failure modes, including fatigue spalling. In addition, retained austenite transformation can lead to an increase in bore diameter, which could result in a loss of fit on the axle journal. Several bearing inner races with various service histories were measured with a Siemens X-ray diffractometer using chromium radiation. Results indicated that the transformation of retained austenite and resultant increase in compressive residual stress are interrelated with load and rolling cycles. Results indicate that the SLF is a useful tool that correlates well with current Association of American Railroads failure criteria.

Quantification of potentially toxic single mineral phases in natural dusts of heterogeneous composition is critical for health hazard assessment. For example, crystalline silica, a human carcinogen, can be present as respirable particles in volcanic ash such as quartz, cristobalite, or tridymite. A method to rapidly identify the proportions of crystalline silica within mixed dust samples, such as volcanic ash, is therefore required for hazard managers to assess the potential risk of crystalline silica exposure to local populations. Here we present a rapid method for quantifying the proportions of single phases in the mineral assemblage of mixed dusts using X-ray diffraction (XRD) with a fixed curved position-sensitive detector. The method is a modified version of the whole-pattern peak-stripping (PS) method (devised by Cressey and Schofield [Powder Diffr.11, 35–39 (1996)]) using an internal attenuation standard (IAS) but, unlike the PS method, it requires no knowledge of other phases present in the sample. Ten synthetic sample mixtures were prepared from known combinations of four pure phases (cristobalite, hematite, labradorite, and obsidian), chosen to represent problematic constituents of volcanic ash, and analyzed by XRD. Results of the IAS method were directly compared with those of the PS method. The proportions of cristobalite estimated using the methods were comparable and accurate to within 3 wt %. The new IAS method involved less sample preparation and processing and, therefore, was faster than the original PS method. It therefore offers a highly accurate rapid technique for determination of the proportions of individual phases in mixed dusts.

The solid-state phase transformation from α- to β-copper phthalocyanine, using isothermal data obtained at T=250 °C and nonisothermal data obtained in the temperature range of 30 °C≤T≤330 °C with a constant heating rate of 1.67 °/min, was investigated by sequential and parametric full quantitative Rietveld analyses. Results obtained in this study show that the parametric Rietveld refinement technique is most suitable and applicable for kinetic studies of isothermal powder diffraction data. On the other hand, the sequential Rietveld refinement technique can give reliable results for the kinetic analysis of nonisothermal data. The main advantages of the parametric Rietveld refinement over the sequential Rietveld refinement are increased robustness against outliers, low weight fractions, and noisy data and an increase in computational speed.