The aim of this work was to compare different excitation modes for the analysis of light elements from carbon (Z = 6) upwards using a total reflection X-ray fluorescence analysis (TXRF) vacuum chamber which allows the attachment of different X-ray tubes and detectors. In the first set of experiments, two water-cooled high-power X-ray tubes with Cr (Z = 25) and Cu (Z = 29) anodes, respectively, were compared with an air-cooled low-power tube with Mo anode (Z = 42) and a thin Be window for the transmission of Mo-L lines. In the first two cases, monochromatic Kα radiation was used for excitation, while in the case of the Mo tube the multilayer acted as a cut-off reflector and part of the Mo bremsstrahlung continuum together with the Mo-L series were used for excitation. Multi-element standards containing elements ranging from Na (Z = 11) to Ti (Z = 22) were analyzed by a silicon drift detector (SDD) with a 300 nm ultrathin polymer window (UTW). Detection limits were calculated and compared for the three excitation modes. The second set of experiments was performed using an air-cooled low-power X-ray tube with Rh anode (Z = 45) in order to show that a conventional SDD with a 25 μm beryllium window can be used for the detection of elements from Na upwards. The use of compact air-cooled low-power X-ray tubes together with Peltier-cooled SDDs with UTW should lead to the development of highly sensitive tabletop vacuum TXRF spectrometers with a design optimized for the analysis of light elements. Detection limits as achieved by vacuum chambers using conventional water-cooled high-power tubes (e.g. Streli et al., 2004) are realistically achievable with the new approach.

The compound Ba4Eu3F17 was prepared by heating pre-dried BaF2 and EuF3 (4:3) at 800 °C for 8 h in static vacuum. The colorless polycrystalline product obtained was characterized by Rietveld refinement of the observed powder diffraction data with a starting model of Ba4Y3F17. The title compound Ba4Eu3F17 crystallizes in rhombohedral lattice with lattice parameters, a=11.1787(4) and c=20.5789(10) Å, Z=3 (Space group R 3, No. 148). The Ba4Eu3F17 structure can be described as an ordered anion-rich fluorite type structure with the formation of Eu6F37 clusters. There are two crystallographically distinct Ba (CN=10, 11) and one distinct Eu (CN=8). The typical Ba(1)–F, Ba(2)–F, and Eu–F bond lengths range from 2.56 to 2.83 Å, 2.54 to 3.25 Å, and 2.24 to 2.49 Å, respectively. The salient feature of the structure is that the EuF8 polyhedra share their corner to form a cubo-octahedron of fluoride ions. The cubic BaF8 polyhedra of BaF2 are modified to Ba(1)–F10 and Ba(2)–F11 polyhedra in this structure. The cubo-octahedron encloses extra fluorine F(8) inside it.

In this work, zinc oxide samples were obtained from hydroxycarbonate by thermal decomposition at 300 °C. Zinc hydroxycarbonate samples were produced by homogeneous precipitation over different periods of time. The method used to obtain zinc oxide produces different morphologies as a function of the precursor precipitation time. Among the obtained particle shapes were porous spherical aggregates, spherulitic needle aggregates, and single acicular particles. This work investigated spherulitic needle-aggregate formation and the correlation among morphology, domain size, and microstrain. Transmission electron microscopy data revealed that the acicular particles that form the spherulitic needle aggregates consist of nanometer crystallites. Apparent crystallite size and microstrain in the directions perpendicular to (h00), (h0l), (hk0), and (00l) planes were invariable as a function of precursor precipitation time. From the results, it was possible to conclude that the precursor precipitation period directly influenced the morphology of the zinc oxide but did not influence average crystallite size and microstrain for ZnO samples. Therefore, using this route, it was possible to prepare zinc oxide with different morphologies without microstructural alterations.

Recently, a new experimental setup for quick X-ray reflectivity (q-XRR) measurements was proposed, which is based on simultaneous recording of an X-ray reflectivity curve over all angles of interest. This new setup for q-XRR allows measurements to be done within seconds, thus permitting studies of the time evolution of chemical, thermal, and mechanical changes at the surfaces and interfaces of different materials. Since the q-XRR measurement setup utilizes an extended X-ray source and detector, it is important to develop models and to account for the following two effects: (i) diffuse scattering associated with different points of the source and (ii) sample curvature. Models accounting for both effects are presented, and their influences on interpretation of the q-XRR measurement results are discussed.

Editor's Note: As part of our plan to reprint previously published papers of great historical interest, the editorial board is pleased to reproduce the following paper by Hanawalt, Frevel and Rinn. This paper was originally published in Volume 10 (1938) of the Analytical Ediction of “Industrial and Engineering Chemistry” and is considered by most diffractionists to be the classic work in qualitative identification of multiphase polycrystalline material. The original publication carried a foreword written by the editor of Industrial and Engineering Chemistry. This foreword ended with this prophetic statement:

“There is reason to believe that this publication, which is made possible in this form by the generous financial assistance of the Dow Chemical Company, will serve to bring this method of analysis into general use in industrial and consulting analytical laboratories.”

In this paper, grandite core with Grs64±1Adr36±1Sps2 composition was crystallographically studied. This core represents zone A of the macroscopically visible five A–E zones of the optically anisotropic Grs58–64Adr36–42Sps2 grandite. The applied procedure includes the detailed analysis of the powder diffraction patterns, and the Rietveld refinements of the crystal structures in a series of 18 space groups and two mixtures, which were followed by the comparative analysis of the R-values, site occupancy factors, and the bond lengths and angles. Synthesis of all of the presented results allows us to undoubtedly conclude that studied grandite is not cubic, neither as monophase nor as multiple phases in a mixture. Namely, it was established that structural dissymmetrization occurred and that it crystallized in the disordered rhombohedral $R\bar{3}c$ or orthorhombic Fddd space groups, whereby the first one is more probable. Beside the established lower symmetry of the studied grandite, which could be treated as the primary cause, the residual strain is also not excluded as the second possible cause for its slight optical anisotropy.

Indexed experimental powder diffraction patterns of Tl,Pb-1223 and Tl-1223 are presented with a method of determining good cell parameters for the former awkward case where c/a almost exactly equals 4. For Tl,Pb-1223, a = 3.814±0.001 Å, c = 15.267±0.005 Å, for Tl-1223, a = 3.814±0.001 Å, c = 15.302±0.005 Å, both tetragonal, space group P4/mmm.

Total reflection X-ray fluorescence spectrometry (TXRF) was used to analyze residual surface contamination on Genesis solar wind samples and to evaluate different cleaning methods. To gauge the suitability of a cleaning method, two samples were analyzed following cleaning by lab-based TXRF. The analysis comprised an overview and a crude manual mapping of the samples by orienting them with respect to the incident X-ray beam in such a way that different regions were covered. The results show that cleaning with concentrated hydrochloric acid and a combination of hydrochloric acid and hydrofluoric acid decreased persistent inorganic contaminants substantially on one sample. The application of CO2 snow for surface cleaning tested on the other sample appears to be effective in removing one persistent Genesis contaminant, namely germanium. Unfortunately, the TXRF analysis results of the second sample were impacted by relatively high background contamination. This was mostly due to the relatively small sample size and that the solar wind collector was already mounted with silver glue for resonance ion mass spectrometry (RIMS) on an aluminium stub. Further studies are planned to eliminate this problem. In an effort to identify the location of very persistent contaminants, selected samples were also subjected to environmental scanning electron microscopy. The results showed excellent agreement with TXRF analysis.

A state-of-art semiconductor technology-based position sensitive area detector, namely D/teX-25, has recently been developed for high-speed and high-sensitivity X-ray diffraction (XRD) analysis of materials. X-ray powder diffraction intensities obtained by a D/teX-25 detector were found to over 50 times higher than those by a conventional scintillation counter. A D/teX-25 detector mounted on a conventional 2 kW XRD system has been used to collect ultrafast XRD data with scanning speeds up to 160°2θ per minute. Ultrahigh-speed XRD is particularly useful for time-resolved dynamical and in-situ studies. A D/teX-25 detector was successfully used on a Rigaku XRD differential scanning calorimetry (DSC) system for simultaneous measurements of XRD and DSC data under controlled temperature and humidity conditions. This has made possible the study of complex and rapid phase transformations of pharmaceutical terfenadine. The D/teX-25 area detector has also been used for recording two-dimensional XRD patterns showing the particle-size effects on α-quartz powder intensities and to obtain digital X-ray topographic images of a complex dislocation network in a Si wafer.

X-ray powder diffraction data, unit cell parameters, and space group for alaptide are presented (a=21.136(4) Å, b=7.212(4) Å, c=6.126(3) Å, space group P212121, cell volume=933.8(8) Å3, and Z=4). All measured lines were indexed and are consistent with the P212121 space group. No detectable impurities were observed.

High quality powder diffraction data were obtained from a specimen containing inseparable impurities, by using single crystal precession photographs to explore all possible reflections for the mineral being studied. In this manner it is acceptable to ignore weak reflections that do not index on the unit cell and that are not observed on the single crystal photographs. Triphylite is given as an example.

Use of the overlap integral in X-ray diffraction (XRD) powder pattern recognition of crystalline materials is presented. The mathematical expression, derived specifically for diffraction data, provides a measure of similarity between two patterns. Each pattern is represented by a normalized mathematical function. The index of similarity, or overlap integral, indicates how faithfully the two functions overlap and ranges from zero to unity, reaching the latter limit when the two patterns become identical.

The X-ray powder diffraction pattern of hydrated lithium monoborate LiB(OH)4, sometimes formulated LiBO2·2H2O, has been obtained. Refinements of indexed reflections yielded the following parameters: a = 9.1732(7)Å, b = 7.9622(6)Å, c = 8.5354(8)Å, space group Pbca, Z = 8, Dx = 1.827, Dm = 1.83 g/cm3. The Smith–Snyder figure-of-merit is F30 = 101(0.007,44).

The performances of Seeman-Bohlin (S-B) and Bragg-Brentano (B-B) diffractometers with flat thin film samples were compared on the basis of equal instrumental aberrations. It was found that the S-B arrangement has only a marginal advantage as regards diffracted intensity, and that both types of diffractometer may be successfully employed for characterization of thin films. Diffraction data obtained with very thin metallic films (down to 30 Å) are included for illustration. In order to eliminate reflections from the singlecrystal substrate in the B-B diffractometer, sample tilting was employed. Provided the tilting angle remains within 0.5°, sample tilting causes only moderate additional broadening of the thin film peaks.

After heat treating, finish machining of the hardened steel represents the last manufacturing step of machine elements. The practically most important operation of grinding is applied to achieve edge zone compressive residual stresses, best surface quality, and dimensional accuracy. Metal removal involves high plastic deformation work. Glide and intersection processes raise the density and produce lower energy substructures of dislocations. The temperature and time behavior of postmachining thermal treatment is analyzed on ground and honed martensitic SAE 52100 rolling bearing steel. Microstructure stabilization is reflected in a large XRD peak width decrease in the surface. The kinetics are modeled by rate-controlling carbide dissolution as the carbon source for Cottrell-type segregation at dislocations. This thermal static strain aging is verified by the formation of a slight white etching surface layer. The model is also extended to consider superimposed thermal dislocation recovery. Both effects are separable. In rolling contact fatigue tests under mixed friction conditions, air reheating below the tempering temperature, which avoids hardness loss, leads to a significant lifetime increase. The effect also occurs after cold working.

Analytical polarized energy-dispersive X-ray fluorescence (PEDXRF) spectrometry (PEDXRFS) represents a substantial advancement over conventional XRF. The higher signal-to-noise commensurate with background lowering and better energy resolution, permits trace analysis for elements with Z ≥ 11. Concomitantly, improvements in analytical software based on the fundamental parameters (FP) approach have improved accuracies and precisions for standard-less analysis (SLA). Two ceramic and soil standard reference materials (SRMs), 98a-Plastic Clay and GSS-1 powders, differed in their intrinsic matrix properties of grain size, bulk, and surface monolayer densities as well as the elemental concentrations. The SRMs were analyzed as powder and as pellets compacted under the same pressure conditions to double the bulk density. Different geometries represented by the sample cup (10, 15, and 24 mm) and pellet (10, 15, and 25 mm) diameters with the same sample thickness (with differing masses and aspect ratios), as well as (for powder samples only) identical low masses (0.5 g) but with varying thicknesses, were analyzed. PEDXRFS combined with TURBOQUANT® (TQ) as SLA-FP enables good quantitative analysis for powders (Z ≥ 13) even for masses significantly lower than recommended, for soil–ceramic samples. Pellets (Z ≥ 12) yielded the best accuracy factor (AF) at high aspect ratio and thicknesses of the matrix analytical depth. Binder in pellets depreciates the AF. TQ needs to adequately quantitate matrix interferences effects, to improve accuracy in the analysis of low atomic numbers, e.g. Na and Mg.

The pharmacy (spezieria) Santa Maria della Scala was founded in Rome by the Discalced Carmelites Order in the 17th century, and during the 18th and 19th centuries it became the official supplier of medicines for Vatican Popes. The laboratory and the cases of this spezieria still preserve glass jars with organic and inorganic materials, which were presumably used for medicine and artistic material preparation, whose composition is unknown to date. A research project was initiated with the aim to study the stored materials and the role that the pharmacy played in regional, national and international contexts. In this manuscript, the compounds were analysed through X-ray powder diffraction with the scope to derive the quantitative mineralogical composition of the inorganic fraction, their possible use in pharmacopoeias and as mineral pigments. Most of the analysed samples are salts (sulphates, chlorides, carbonates, phosphates, borates, sulphides), sulphates being the predominant class; oxides were also detected.

A critical review of all the reported structures and powder diffraction patterns in the uranium telluride system has been undertaken. Our recommendations are:

1. Structures that are correct:

• Cubic – UTe: no experimental pattern exists. Retain calculated 15–865.

• Cubic – U3Te4: retain poor quality 12-610 but adopt the pattern calculated here.

• Cubic U2Te3: no experimental pattern exists. Adopt pattern calculated here.

• Orthorhombic UTe2: Adopt the new pattern of Boehme et al.

• Monoclinic αUTe3: Adopt the new pattern of Boehme et al.

• Orthorhombic βUTe3: Adopt the pattern calculated here.

• Orthorhombic UTe5: Adopt the new pattern of Boeheme et al.

2. Structures in need of refinement:

• Orthorhombic U2Te3: Adopt pattern calculated here over 34-807.

• Hexagonal U7Te12: Adopt pattern calculated here but retain 24-1368.

• Orthorhombic UTe1.78: Adopt pattern calculated here and retain our modified 21-1404 reported for U4Te7.

• Orthorhombic UTe2.5: Adopt pattern calculated here.

• Orthorhombic UTe3.4: Accept recent pattern of Boehme et al.

3. Phases for which no structures or reliable patterns exist:

• Orthorhombic U3Te4: no published pattern.

• Tetragonal U3Te5: three patterns 21-1407, 34-766 and 34-896 exist but all are of very poor quality.

4. Phases which probably do not exist:

• Tetragonal UTe1.77

• Tetragonal UTe2

• Cubic UTe2

• U3Te7 (21-1402)

• U3Te8 (21-1406)