Six A-type zeolites: NaA, MnNaA, CoNaA, NiNaA, ZnNaA, CdNaA have been characterized by X-ray powder diffraction. The zeolites with selected divalent cations have been synthesized by a very careful ion-exchange process using very high quality NaA zeolite. Experimental 2θ peak positions, relative peak intensities, values of d and Miller indices as well as a unit cell parameter are reported.

Rigid bodies provide a way to simplify the model used in a crystallographic refinement by removing parameters that describe degrees of freedom that are unlikely to change based on chemical experience. The GSAS software package provides a powerful implementation of rigid bodies that allows for refinement of classes of bond lengths, grouping of bodies to further reduce parameterization and where atomic motion can be described from group displacement parameters (TLS) representation. However, use of rigid bodies in GSAS is complex to learn and time-consuming to perform. This paper describes how the rigid body definition process has been simplified and extended through implementation in the EXPGUI interface to GSAS.

Samples of the superconducting compound (Hg,Re)–1223 of nominal composition Hg0.82Re0.18Ba2Ca2Cu3O8+δ and different oxygen contents were studied using X-ray absorption and diffraction techniques. In the synthesis process, treatments under different ratio oxygen/argon gas mixtures of 5%, 10%, and 15% O2 resulted in samples named as Sample A, Sample B, and Sample C, respectively. It was determined by using the XANES technique that in these compounds the Re cation has valence +7. The study by EXAFS determined that the octahedral coordination is distorted and the distances of Re–O bonds are of the order of 1.85 A˚ for equatorial oxygen and 2.10 A˚ for the apical ones. The Rietveld refinement of X-ray powder diffraction data revealed that the studied samples presented segregation of two superconducting phases with space group P4/mmm and distinct lattice parameters, also confirmed by anomalous X-ray scattering. The main phase was associated to the phase (Hg,Re)–1223 with higher oxygen content and the secondary superconducting phase was associated with the undoped Hg–1223 phase. Measurements of ac magnetic susceptibility showed that the sample treated under 10% O2 atmosphere presented the best superconducting properties.

A new cobalt molybdate with the formula NaCo2OH(H2O)(MoO4)2 was synthesized by hydrothermal reaction at 200 °C and was found to possess the Φx type structure. The crystalline system of this material is monoclinic and its cell parameters are a=9.3792 (2), b=6.3331 (1), c=7.6281 (2) Å and β=115.832°, obeying the C2/m space group symmetry.

X-ray diffraction analysis on small samples or micro-area of large samples is always a challenge due to weak diffraction and poor statistics, especially when dealing with samples containing large grain size, inhomogeneous phase distribution, and preferred orientation. Two-dimensional X-ray diffraction has many advantages in microdiffraction analysis. A two-dimensional detector can collect a large amount of data both in terms of speed and angular coverage. This paper covers some aspects about instrumentation of two-dimensional X-ray diffraction and its applications in phase identification and stress analysis on small samples and micro-area of large samples.

Powder diffraction pattern of SP-1 graphite has been obtained using synchrotron X-ray diffraction. Unit cell dimensions were calculated using a least-squares analysis that refined to a |Δ2θ°| of no more than 0.007. A hexagonal cell was determined with a space group of P63/mmc (194), a=2.4617(2) and c=6.7106 (4) Å. The Smith/Synder figure of merit is 167 based upon 11 peaks, which indicates that the quality of this data set is superior to the existing PDF card for graphite, 41-1487. It is also emphasized that the interlayer spacing of graphite should be 3.355(1) Å. Using GAS and EXPGUI codes, a new set of calculated powder diffraction data based upon the interlayer spacing of 3.555 Å is generated. A comparison with the current calculated card, 75-1621, has also been made.

The X-ray powder diffraction pattern for a new precursor in the synthesis of pyridyl tetrahydroquinolines was determined. 4-N-(4-methylphenyl)amine-4-(3′-pyridyl)-1-butene is monoclinic with refined unit cell parameters a=16.554(5), b=7.204(2), c=12.257(3) Å, β=99.76(2)°, V=1440.5(4) Å3, Z=4, and Dx=1.098 g/cm3, with space group P21/n (No. 14).

Micro X-ray fluorescence (MXRF) offers the analyst a new approach to materials characterization. The range of applications is expanding rapidly. Single point analysis has been demonstrated for nanoliter volumes with detection limits at the 0.5 ng level. MXRF can be used as an element specific detector for capillary electrophoresis. Elemental imaging applications include analysis of sample corrosion and polymers, use as a combinatorial chemistry screening tool, and integration with molecular spectroscopic imaging methods to provide a more comprehensive characterization. Three-dimensional elemental imaging is a reality with the development of a confocal X-ray fluorescence microscope. Stereoview elemental X-ray imaging can provide unique views of materials that flat two-dimensional images cannot achieve. Spectral imaging offers chemical imaging capability, moving MXRF into a higher level of information content. The future is bright for MXRF as a materials characterization tool.

Advances in X-ray texture solutions require new methods and descriptions for the texture analysis process, e.g., when using general area detector diffraction systems. A new method is presented that defines a general pole figure resolution and provides the possibility to optimize strategies for efficient pole figure data collection. Application of the new method improves resolution and (!) speed. New software enables simultaneous monitoring of pole and detector space. This allows a fundamentally better understanding of the collected information, e.g., in situations where peaks overlap or high backgrounds compromise data quality.

Elevated-temperature X-ray diffraction (XRD) was used to evaluate residual stresses in aluminum thin films on Si(100). The films with a thickness of 2 μm were deposited by magnetron sputtering at different temperatures, and XRD measurements were carried out with the heating stage DHS 900 mounted on a Seifert 3000 PTS diffractometer. The strains were characterized always in temperature cycles from room temperature up to 450 °C with steps of 50 °C. Stress values in weakly textured thin films were calculated using the Hill model, applying temperature-dependent X-ray elastic constants of aluminum. The thin films exhibit specific temperature hysteresis of stresses depending on the deposition temperature (being from the range of 50 °C–300 °C). The results allow us to quantify contributions of intrinsic and extrinsic stresses to the total stress in the layers as well as to evaluate phenomena related to plastic yield. The comparison of the data from thin films deposited at different temperatures indicate a dependence of intrinsic stresses on the substrate temperature during deposition as well as the presence of the plastic yield in films during the cool-down after deposition

The potassium μ-Oxo-bis(oxodiperoxovanadate)(4-) hydrate K4[O{VO(O2)2}2]*H2O was prepared, and its X-ray powder diffraction patterns have been recorded at room temperature. The unit cell parameters were refined to a=6.7097(1) Å, b=9.9574(1) Å, c=15.8250(3) Å, β=93.69(6)°, space group P21/c (14). The sample of K4V2O11*H2O was characterized by IR spectroscopy and analytical investigation. Results of crystal structure refinement by Rietveld method are presented; final RF and Rwp are 13 and 16%, respectively.

A novel sealed gaseous parallel plate avalanche chamber detector is described which is significantly less prone to discharges and can consequently achieve high gas gains at high counting rates. The detector has demonstrated stable gains greater than 104 at counting rates in excess of 107 counts/mm2 s.

X-ray powder diffraction (XRD) is utilized for the determination of polymorphism in crystalline organic materials. Though convenient to use in a laboratory setting, XRD is not easily adapted to in situ monitoring of synthetic chemical production applications or thin film depositions. Near-infrared spectroscopy (NIR) can be adapted to in situ manufacturing schemes by use of a source/detector probe. Conversely, NIR is unable to conclusively define the existence of polymorphism in crystalline materials. By combining the two techniques, a novel simultaneous NIR/XRD instrument has been developed. During material’s analysis, results from XRD allowed for the determination of the existence of polymorphic phases, and NIR data were collected as a fingerprint for each of the observed polymorphs. These NIR fingerprints allowed for the development of a library, which can be referenced during the use of a NIR probe in manufacturing settings. The NIR/XRD instrument was also used to monitor materials during exposure to ambient air. XRD can detect crystalline phase changes and NIR can monitor solvent loss and/or water uptake.

The compound Ba4Nd3F17 was prepared by heating predried BaF2 and EuF3 (4:3) at 900 °C for 8 h in static vacuum. The polycrystalline sample obtained was characterized by Rietveld refinement of the observed powder diffraction data with the starting model of Ba4Y3F17. This compound crystallizes in a rhombohedral lattice with unit-cell parameters, a=11.2818(3) and c=20.7788(11) Å, Z=6, (Space group R 3, No. 148). The Rp, Rwp and Rexp factors were 9.5%, 12.9% and 10.9%, respectively.

The aim of this study is to analyze the mechanics of a new class of metal/ceramic composites on a mesoscopic length scale. These composites are produced by melt infiltration of porous ceramic preforms produced by freeze casting and subsequent sintering. This production route has a high application potential since it offers a cost-effective way to obtain composites with ceramic content in the 30 to 70 vol. % range. The as-produced material exhibits a hierarchical domain structure with each domain composed of alternating layers of metallic and ceramic lamellae. Residual stresses present in all phases of the composite produced by infiltrating alumina preforms with a eutectic aluminum-silicon alloy have been measured. Integral as well as spatially resolved measurements were carried out on single-domain samples at the high-energy, energy-dispersive diffraction (EDDI) beamline at the synchrotron radiation source BESSY (Berlin, Germany). Results show that strongly fluctuating residual stresses are introduced by the production process, which can be rationalized by taking into account the thermal expansion mismatch of alloy and preform.

The change in the orthorhombic structure of PbZrO3 was studied as a function of the La substitution for Pb and Ti substitution for Zr. Two types of changes can occur: (1) a change in the atom coordinates toward the positions for a perfect cubic perovskite lattice; and (2) a change of orthorhombic unit cell parameters so that ao, bo, and co exactly fit with the cubic cell parameter ac. Therefore, ao=ac√2, bo=ac.2√2, and co=ac.2, where ao, bo, and co are the orthorhombic cell parameters, and ac is the cubic cell parameter. Substitution of Pb by La in the orthorhombic PLZT leads to both a change in atom coordinates and a change in unit cell parameters toward the perfect cubic structure, especially for La≥4. Substitution of Zr by Ti in the orthorhombic PLZT leads to similar atom coordinate changes, but the unit cell parameters do not change. The composition 0/92.5/7.5 contains a major tetragonal phase and a minor orthorhombic phase. There are only small differences in the orthorhombic structure between the A and the B composition of PLZT. The A composition has a structure closer to the cubic structure than the B composition.

Weight fractions of four dominant phases (C3S, C2S, C4AF, and C3A) present in five industrial clinkers were estimated by a series of neutron and X-ray Rietveld refinements. Calculated powder patterns were derived from the structural data for monoclinic and triclinic C3S, monoclinic C2S, orthorhombic C4AF, cubic C3A and MgO. Neutron diffraction data were collected with the high resolution E9 diffractometer (BENSC) using two different wavelengths, X-ray diffraction data with a high resolution transmission diffractometer. Elemental composition of the samples obtained by ESEM/EDX technique were in a good agreement with the data delivered by the producers. Convergence of the refinements was remarkably different for X-ray and for neutron data. Several refinements were not completed due to numerical instabilities. Neutron refinements were found to be more stable than X-ray, but there was not any notable difference in the final estimated phases’ compositions. Calculated absolute deviates of phases’ weight fractions were mostly within ±10%, which for the less abundant phases corresponded to relative deviations within ±50%. © 2004 International Centre for Diffraction Data.