Wavelengths and intensities are reported for the K series of magnesium, aluminum, and silicon, using primary excitation. Included in the tabulation for magnesium and aluminum are the diagram lines α1α2 and β and the nondiagram lines α', α3, α4, α5, and α6. Data are given for the Si K spectral lines α1α2, β, α3, and α4, Spectra are shown and line positions and intensities are detailed using both metal and oxide as the X-ray source. Significant differences are seen between metal and oxide spectra especially in wavelength and shape of Kβ, and large changes are noted in the intensities of some satellite lines. Spectra from a number of aluminum intermetallic compounds are discussed, including line positions, satellite line ratios, and line shape. It is shown that the spectra fall into three predictable groups; good conductors; poorer conductors; and semiconductors and insulators. Structurally similar compounds give similar spectra. For instance, line positions, shapes, and intensities are nearly identical for NbAl3 and TaAl3. It is not possible to correlate spectra with aluminum coordination number, and previous work using Kα, where secondary excitation was used, could not be reproduced using primary excitation. Possible reasons for this disagreement are discussed.

Using protons in the MeV range as excitation source and a high resolution Si(Li) detector, X-ray emission spectroscopy is shown to be capable of analysing many elements with Z > 15 simultaneously at the 10-12 g level, This work discusses a theoretical lower limit of detection at moderate proton energies and gives examples of possible applications: analysis of the elemental composition of air-borne particles as a function of particle size, oil slick identification, and analysis of water and blood serum.

Hydrothermal formation reaction of tobermorite in the autoclaved aerated concrete (AAC) process has been investigated by in situ X-ray diffraction. High-energy X-rays from a synchrotron radiation source in combination with a newly developed autoclave cell and a photon-counting pixel array detector were used. XRD measurements were conducted in a temperature range 100–190°C throughout 12 h of reaction time with a time interval of 4.25 min under a saturated steam pressure. To clarify the tobermorite formation mechanism in the AAC process, the effect of Al addition on the tobermorite formation reaction was studied. As intermediate phases, non-crystalline calcium silicate hydrate (C-S-H), hydroxylellestadite (HE), and katoite (KA) were clearly observed. Consequently, it was confirmed that there were two reaction pathways via C-S-H and KA in the tobermorite formation reaction of Al containing system. In addition, detailed information on the structural changes during the hydrothermal reaction was obtained.

A Debye–Scherrer film that had been stored for several years in an office environment file cabinet was observed to be shriveled and distorted in appearance. An investigation using X-ray diffraction was carried out to determine the cause of the physical change in the film strip. As expected, silver phases were detected, due to the photographic capture layer coated on the surface of all traditional X-ray films. An unexpected result was the presence of cellulose II, an indication that a chemical change had occurred in the original cellulose triacetate (CTA) polymer film base. Laboratory experiments used to demonstrate an accelerated method of deacetylation of CTA were carried out, resulting in phase pure cellulose II. A density functional geometry optimization allowed for the generation of an improved structural model for cellulose II. Calculated and experimental powder patterns for cellulose II have been submitted to the International Centre for Diffraction Data for inclusion in future releases of the Powder Diffraction File.

Ba3−xSrxTb3−xCexO9 (x = 1 and 1.5) ceramics (BSTC) with a relative density of 93% and a grain size distribution of 0.2–3 µm were prepared by the mixed-oxides reaction route. The crystalline structures, microstructures, valence states, and electrical properties of two ceramics were analyzed using X-ray powder diffraction (XRPD), scanning electron microscopy (SEM), X-ray photoelectron spectroscopy (XPS), electron paramagnetic resonance (EPR), and electrical measurements. Rietveld analyses of XRPD patterns show that BSTC1 is indexed as a trigonal structure with the space group R-3c, and BSTC3/2 is indexed as an orthorhombic perovskite structure with the space group Pmcn. The EPR, XPS, and electrical conductivity results confirm that Ce and Tb ions in BSTC exist as Ce4+ and mixed-valence states of Tb4+/Tb3+, respectively. At room temperature, the two BSTC ceramics exhibit a similar semiconducting behavior. The relationships between electrical conductivity and temperature/frequency are provided. The defect chemistry is discussed.

Quantitative phase analysis (QPA) using neutron powder diffraction more often than not involves non-ambient studies where no sample preparation is possible. The larger samples and penetration of neutrons versus X-rays makes neutron diffraction less susceptible to inhomogeneity and large grain sizes, but most well-characterized QPA standard samples do not have these characteristics. Sample #4 from the International Union of Crystallography Commission on Powder Diffraction QPA round robin was one such sample. Data were collected using the POWGEN time-of-flight (TOF) neutron powder diffractometer and analysed together with historical data from the C2 diffractometer at Chalk River. The presence of magnetic reflections from Fe3O4 (magnetite) in the sample was an additional consideration, and given the frequency at which iron-containing and other magnetic compounds are present during in-operando studies their possible impact on the accuracy of QPA is of interest. Additionally, scattering from thermal diffuse scattering in the high-Q region (<0.6 Å) accessible with TOF data could impact QPA results during least-squares because of the extreme peak overlaps present in this region. Refinement of POWGEN data was largely insensitive to the modification of longer d-spacing reflections by magnetic contributions, but the constant-wavelength data were adversely impacted if the magnetic structure was not included. A robust refinement weighting was found to be effective in reducing quantification errors using the constant-wavelength neutron data both where intensities from magnetic reflections were ignored and included. Results from the TOF data were very sensitive to inadequate modelling of the high-Q (low d-spacing) background using simple polynomials.

A new polymorph of iodic acid, δ-HIO3, synthesized via aerosol spray pyrolysis was characterized with powder X-ray diffraction and its crystal structure was solved. We find that a previously misidentified phase of I4O9 hydrate is in fact a new polymorph of HIO3, which crystalizes in the orthorhombic space group P212121.

This paper presents an example of comparing geochemical and mineralogical data by means of the statistical analysis of the X-ray diffraction patterns and the chemical compositions of bulk samples. The proposed methodology was tested on samples of metasomatic rocks from two geologically different objects. Its application allows us to mathematically identify all the main, secondary and some accessory minerals, to qualitatively estimate the contents of these minerals, as well as to assess their effect on the distribution of all petrogenic and investigated trace elements in a short period of time at the earliest stages of the research. We found that the interpretation of the results is significantly influenced by the number of samples studied and the quality of diffractograms.

This paper is devoted to the X-ray diffraction study of bone fragments of Permian parareptile Deltavjatia vjatkensis obtained from the Kotelnich vertebrate fossil site, one of the richest of the Permian period, which is characterized by the excellent preservation of fossil remains because of their burial in a silty anaerobic environment similar to modern bogs. The bone is well-preserved and consists of fluorapatite, calcite, quartz, and dolomite. The refined apatite unit-cell parameters of a and b-axis (9.3526 ± 0.0001 and 9.3587 ± 0.0001) Å and c-axis (6.8930 ± 0.0001 and 6.8968 ± 0.0001) Å correspond to F-apatite. Crystallinity index determined as the full width at half maximum of the 002 reflection in degrees 2θ is 0.266–0.250, which is typical for Mesozoic vertebrate bones. Apatite crystallite size (length 70.3–74.9 nm, width 30.7–30.3 nm) in fossil pareiasaur bone is larger than in subfossil and recent mammal bone and is in a good agreement with the values for seismosaurus bone. Both crystallite size and aspect ratio (2.3–2.5) are independent of the fossil pareiasaur bone length.

A polycrystalline sample of Ca4ZrGe3O12 was synthesized using the nitrate–citrate method and heated at 850–1100 °C. Structural refinement based on X-ray powder diffraction data showed that the crystal structure is of the garnet type with a cubic unit-cell parameter [a = 12.71299(3) Å] and the space group Ia$\bar 3$d. The structural formula is presented as Ca3[CaZr]octa[Ge]tetraO12.

Baileychlore is Zn-end member trioctahedral chlorite, named by Audrey C. Rule and Frank Radke in 1988 for the honor of Professor Sturges W. Bailey of the University of Wisconsin – Madison, USA. Baileychlore occurs as dark green chlorite on calcite veins from garnet-vesuvianite skarn clasts at Red Dome ore deposit, Chillagoe, Queensland, Australia. The baileychlore has been studied by using powder X-ray diffraction (XRD), transmission electron microscopy (TEM), and X-ray energy-dispersive analytical electron microscopy analyses to determine crystal structure and interstratified layers. Baileychlore with stacking disorder displays streaking reflections of 0k0 (≠6n) hhl (h ≠ 3n). Unit-cell parameters for baileychlore (type I polytype) with a space group of C$ \bar 1$ are: a = 5.351(3), b = 9.266(5), c = 14.418(8) Å, α = 89.741(3)°, β = 96.741(4)°, and γ = 90.122(2)°. The strong lines of the measured XRD pattern [d(Å)(I)(hkl)] are: 14.331(7.151)(90.5)(002); 4.574(23.2)(1$ \bar 1$0, 11$ \bar 1$); 3.572(38.5)(004); 2.653(31.4)($ \bar 1$31, 200, 13$ \bar 1$); 2.406(49.4)(202, $ \bar 1$33, 13$ \bar 3$); 1.543(27.6)($ \bar 3$31, 060, 33$ \bar 1$), respectively. Reitveld refinement provides a composition (Zn2.49Al0.09Fe2+ 0.09□0.33)0.61− for the octahedral sheet and (Si3.53Al0.47)0.47− for the tetrahedral sheets within the 2:1 layer with (Al1.08Fe1.08Mg0.84)1.08+ for the interlayer sheet. The refinement results indicate that baileychlore is an intergrowth of type I and II polytypes. High-resolution TEM images show stacking disorder of baileychlore with small amount of isolated smectite layers.

New powder X-ray diffraction data of Ca12Al14O32F2 (C11A7f), a cementitious compound, were collected on a conventional X-ray powder diffractometer; the cubic cell parameter is a=11.96269(6) Å, volume 1711.93(2) Å3 (space group I-43d (No. 220)). The strongest lines are 4.887(100), 2.676(95), 2.992(46), 2.443(46), 2.185(37), 3.198(32), 1.599(26), and 1.941(25). Reported intensities are validated by Rietveld analysis. The new data consist of measured intensities and cover a wider 2θ angular range with respect to the calculated PDF 25-394 and the indexed PDF 36-678: experimental, calculated, and difference patterns are reported together with crystal-chemical considerations.

A new diffraction pattern of the high-temperature and high-pressure polymorph Mg3(PO4)2-III (PDF 43-500) is given and indexed on the basis of a single-crystal structure refinement. It allows diffractogram indexing of the isostructural high-temperature and high-pressure form of Co3(PO4)2 (PDF 43-499).

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.

Notwithstanding expectations of a pure pyrochlore structure (cubic space group Fd3m (227) with Z=8) terbium titanate turns out, like many pyrochlore compounds, to be slightly disordered in the cation and the oxygen lattice so that it partially (for 10%) resembles a structure with fluorite properties (space group Fm3m (225) with Z = 2).

A series of mixed fluoride compositions with PbF2 and ScF3 were prepared by heating the intimate mixtures of component fluorides at 600 °C for 10 h followed by slowly cooling to room temperature. The products obtained were analyzed by powder XRD to reveal the phases present in them and hence the low-temperature phase equilibria in the PbF2-ScF3 system. The phase equilibria show the fluorite-type solid solution up to the composition of about 15 mol% of ScF3 in the PbF2 lattice. The unit cell volume decreases with increasing ScF3 contents in the fluorite-type solid solutions. Beyond the solubility limit, the biphasic mixture of the cubic fluorite-type solid solution and leftover ScF3 is found to exist.

50-50 atomic percent lead telluride (Altaite), grown by the vapor transport method, was examined with a well aligned Rigaku horizontal beam diffractometer. PbTe is cubic (precise lattice parameter ao = 6.4591(5)Å) with an space group and a calculated density of 8.253 g/cm3. Fully indexed powder diffraction data are presented.

In this paper we present a high temperature heating device, working under defined environmental conditions, for a Siemens D500 Bragg–Brentano powder diffractometer. The powder sample is prepared in a flat mould on a metal block consisting either of copper or of platinum depending on the temperature range selected for investigations. Although the heating cell can be used separately under ambient conditions up to sample temperatures of 1000 °C, it is possible to work under defined environmental conditions in the temperature range between 20 and 200 °C and up to a water vapour pressure of 1000 mbar. For that purpose a special cover for the in situ control of temperature and water vapour pressure has been constructed. It is important to note that the three sample conditions (sample temperature, gas temperature, and gas humidity) can be adjusted separately by the user. Current studies have shown that the described X-ray heating device is a powerful tool to study dehydration reactions in the frame of fundamental research as well as to understand industrially relevant processes concerning dehydration reactions and their mechanisms.

Data for the standard material NBS SRM 674, TiO2, were collected on two diffractometers: a) a Philips PW 1050/37 standard diffractometer of the Bragg-Brentano type equipped with a post diffraction curved Ge monochromator, b) a Stoe Stadi P diffractometer of transmission type equipped with a curved incident beam Ge monochromator. Both monochromators were set to select pure CuKα1 radiation. The reflection type instrument gives a much larger peak to background ratio than the transmission instrument, for which the background is much higher than with the reflection instrument. Rietveld refinements were carried out on both data sets with the programs DBWS-9807 and general structure analysis system (GSAS). The structural parameter of the oxygen atom of rutile depends neither on data set nor program, whereas, e.g., thermal displacement parameters seem to depend on both data set and program.

The crystal structure of the Aurivillius compound Bi2BaTa2O9 prepared via the chemical route was determined by direct methods using EXPO97, and refined using the Rietveld method with conventional X-ray diffraction data. The structure was found to be tetragonal (space group I4/mmm, number 139) and Z=2, isomorphic of the Bi2BaNb2O9 reported by Blake and co-workers in the literature (1997). Two refinements were performed using the two asymmetry functions of DBWS-9807 (release 20/May/99). The unit cell for each case are: a=3.932 22(6) Å, c=25.5053(6) Å (RA) and a=3.932 50(7) Å, c=25.5069(6) Å (RCF). The differences for atom positions, interatomic distances and angles are in the range of one standard deviation. Final agreements factors are: Rwp=7.97%, S=1.84, RBragg=4.28%(RA), Rwp=7.98%, S=1.84, RBragg=4.30%(RCF). The occupancies of Ba and Bi in site 2b were refined but constrained to have their summation equal to 1.00. The same constraints were applied to the Ba and Bi of the 4e site. The results show that on site 2b there are 70% of Ba and 30% of Bi and on the site 4e there are 82% of Bi and 18% of Ba. The charge equilibrium is maintained for one standard deviation of the site occupancies.© 2000 International Centre for Diffraction Data.