In the preparation of ceramic SrCe0.95Yb0.05O3−α great care was taken to obtain a homogeneous, carbonate free and dense material of exactly the given composition. The material is an important high-temperature protonic conductor (HTPC). X-ray powder diffraction data are reported. The cell parameters obtained are a=6.007(2) Å, b=12.296(3) Å, c=8.588(2) Å, cell volume 634.4(1) Å3, Z=8. The space group is most probably Pnma (62) and Dx=5.806(2) g/cm3. The bending strength of the sintered dense material is 175±6 MPa.

Two structurally related compounds, Tl3Li(MoO4)2 and Tl3Li(WO4)2, have been synthesized by solid state reaction. Space group (P63mc) and unit-cell parameters [a(Å)=6.00392(3); c(Å)=15.8203(1) and a(Å)=6.03484(3); c(Å)=15.81759(9), respectively, for Tl3Li(MoO4)2 and Tl3Li(WO4)2] were determined. Powder diffraction data for each phase are reported.

Characterization of some crystalline species present in atmospheric particulate matter can be investigated by an X-ray diffractometric technique. According to the analytical strategy, filtering media suitable for collecting airborne particles must be selected. In order to recognize the X-ray diffraction patterns and consequently the inherent analytical interference of filtering media, a systematic X-ray diffraction evaluation of several substrates was performed. Although artifact formation during ambient sampling can occur on quartz and glass fiber filters, these filters were also included in the diffractometric characterization. In this work, commercial filters were thermally treated and submitted to X-ray diffraction scanning. Results have shown pronounced variations in the diffractometric profiles of each thermally treated substrate. The selection criteria for choosing the filtering media was established by considering their chemical and physical properties and also the crystalline species to be collected on them.

New solid solution phases in the (Y,Ca)(Cr,Co)O3 system have been synthesized and characterized by powder X-ray diffraction. The selected compositions in this system were prepared by the modified Pechini method. Powder-diffraction patterns were prepared.

Precise X-ray powder diffraction data are given for two germanides, CoGe and Co5Ge7. The refined unit cell parameters for CoGe are a=11.630(1) Å, b=3.8014(3) Å, c=4.9347(3) Å and β=100.889(8)° (space group C2/m, Pearson symbol mC16) with volume of the unit cell 214.24(2) Å3; the figures of merit are M20=96, F30=77 (0.0085, 46). The refined unit cell parameters for Co5Ge7 are a=7.6262(4) Å and c=5.8017(5) Å (I4mm, tI24) with volume of the unit cell 337.42(3) Å3; the figures of merit are M20=204 and F22=130(0.0068, 25). The dependence on composition of the unit cell parameters of CoGe is discussed in terms of specific defect structures.

Algorithms are presented to correct intensities affected by divergence slit attenuation in the low 2θ region of Bragg–Brentano powder diffractometers with rectangular sample holders. The intensity loss below a limiting angle 2θ1 occurs when the X-ray beam cross section exceeds the sample surface at decreasing angles. For identification purposes, the observed intensities can be scaled up to values comparable with intensities unaffected by divergence slit effects.

Metal mepirizole perchlorates, M(C11H14N4O2)3 (C104)2 where M = Co(II) and Ni(II) have been investigated by means of X-ray powder diffraction. Unit cell dimensions were determined by indexing programs from diffractometer data. Refined cell parameters (monoclinic with a C-centered cell), calculated density and Z values are presented.

The calculated XRD profiles of alite (impure Ca3SiO5, the major phase in Portland cement) derived from seven postulated crystal structures for alite were compared with a measured alite profile, extracted from the XRD pattern of a standard Portland cement. Only two of these profiles were found suitable for multiphase Rietveld phase quantification, namely those given by the monoclinic superlattice and triclinic models. These, however, gave very slow computing times because the large low-symmetry structures generated many X-ray reflections over the pattern. Also tested was an “observed” standard profile for alite, derived from experimental alite profiles, and generated using the (hkl) file feature of the SIROQUANT P.C. quantitative analysis system. This file was based on rhombohedral pseudosymmetry and contained very few (hkl) reflections, compared to the low-symmetry models (64 reflections instead of 951 for the monoclinic and 1691 for the triclinic models, respectively). The latter standard profile gave the best fit to the known phase concentrations and gave computing times which were shorter by factors of 2.5 and 4.9 than those for the monoclinic and triclinic standard profiles, respectively.

The thermal decomposition of aqueous manganese nitrate has been studied under a range of experimental conditions to scientifically assess the pyrolysis processes employed by the tantalum capacitor industry. The crystalline phase and form of the manganese oxides produced are compared by X-ray diffraction and scanning electron microscopy. Those experimental conditions producing materials with the lowest resistivity are identified. The technological significance of the decomposition process is discussed and initial results from a novel pyrolysis technique are presented.

The solid solutions Y2−xDyxO3 (x=0.20,0.50,0.74,1.40,1.80) were obtained by ceramic technology. The crystal structures were refined from X-ray and neutron diffraction data measurements in the cubic space group Ia3 by the Rietveld method. The unit cell dimensions varied from 10.6056(4) Å to 10.6624(1) Å. The structure characteristics were analyzed in relation to the concentration of the magnetic ion. The selected cation–anion–cation bonds, important for the understanding of the superexchange interaction and the magnetic properties, are given. In all samples the Dy3+ ions are randomly distributed in the cation sites 8(b) and 24(d). Comparing the random cation distribution in Y2−xDyxO3 and the preferential distribution in Y2−xGdxO3, it has been concluded that the type of distribution depends on the difference of the lattice constants between RE2O3 and Y2O3. Hence, in this cubic Mn2O3-type of structure, a preferential distribution can be expected in Y2−xNdxO3, Y2−xSmxO3, Y2−xEuxO3, Y2−xLuxO3, and a random distribution in Y2−xHoxO3.