An X-ray diffraction peak-broadening analysis of four oxides is described: La2CuO4 and La1.85M0.15CuO4 (M = Ca,Ba,Sr) high-Tc superconductors. The diffraction line profiles were fitted with a convolution of specimen and instrumental functions, and the specimen peakbroadening angular dependence was analyzed with the Warren-Averbach method. It was found that microstrains and incoherently diffracting domains are highly anisotropic. In the superconductors, stacking-fault probability increases with increasing Tc; microstrain decreases. In La2CuO4, different broadening of (h00) and (0k0) reflections is not caused by stacking faults; it might arise from lower crystallographic symmetry.

The correct formulas for geometrical factors for correction of diffracted intensities in Seemann-Bohlin diffractometry were tested. A Huber 653 goniometer, gold and titanium nitride layers, white tin, and rutile as specimens were used in the reflection mode. A Huber 642 goniometer and olivine as a specimen were used in the transmission mode. It was found that, due to a variable specimen-detector distance during 2θ scan, the variable efficiency of the Soller slits in the diffracted beam must be taken into account. The model describing this effect analytically is presented. As a final test the structures of white tin, rutile, and olivine were refined from the measured data corrected for different factors.

After regeneration, the catalyst UOP-R-62 was used for conversion of reforming benzine. The percentage of conversion benzine fraction was considerably smaller than that of the new catalyst sample. To determine the cause of catalyst deactivation, in addition to standard methods of analysis, X-ray diffraction and scanning electron microscopy were used. Real and model samples of UOP-R-62 were analysed. Real samples were prepared with the new catalyst, a used and regenerated catalyst with good activity and a deactivated catalyst. Model samples were prepared from the new catalyst by heating at 400–1100 °C in a porcelain crucible in a muffle furnace for 1 h. Prepared samples were measured in a Philips diffractometer system and examined in a scanning electron microscope. The obtained diffractometer patterns, FWHM value of the 440 reflection of γAl2O3, electron micrographs and images of emitted characteristic X-rays were mutually compared. Only the values obtained from the deactivated catalyst differed from the others. Besides reduced broadening of the 440 line the material exhibited new X-ray diffraction lines, a change in phase composition, and modifications in morphology and microstructure. These changes are an indication that overheating of individual spheres of catalyst UOP-R-62 to a temperature of 700—1100 °C or higher caused their deactivation.

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.

X-ray diffraction quantitative phase analysis is a technique widely used in materials science and engineering research. The method proposed by Zevin [L. S. Zevin, J. Appl. Cryst. 10, 147 (1977)] has proven very useful in practice because standards or pure crystalline phases are not needed, but, Zevin only described the case of n samples, each of which contain different concentrations of the same n phases. An extension of this method, in which the reference samples could contain less phases than the analyzed sample is proposed in this paper. The absence of phases in reference samples is not arbitrary but depends on certain conditions. The conditions required to solve the equations are discussed in detail using the concepts of the set theory, and the results of confirmation experiments agree well with the theory.

An X-ray powder diffraction quantitative analysis has been developed to determine the relative amounts of the principal crystalline phases (α-Li2SiO3, α-Li2Si2O5 and the α-cristobalite form of SiO2) contained in selected Li2O–SiO2 glass-ceramics. The analysis was extended to estimate the amorphous-to-crystalline content ratio of individual samples. The method utilized is an external-standard intensity ratio technique that employs cristobalite, a component common to each sample, for a standard.

This paper further confirms that the direct measurement of diffraction angles at different temperatures by using the X-ray diffractometer is better than measurement of the lattice parameters for the rapid and accurate determination of the linear thermal expansion of silicon. High purity silicon has the linear expansion coefficient, α= (2.45±0.05) × 10−6/°C at room temperature. This value does not change for doped P-type and N-type silicon.

The decomposition reactions of two zirconium hydroxide nitrates Zr(OH)2(NO3)2·(4+x)H2O and α-Zr(OH)2 (NO3)2·(1+x)H2O (0≤x≤1) have been studied by thermogravimetric analysis and high-temperature X-ray powder diffractometry (HTXRD), in nitrogen gas environment. The decomposition reaction sequences were clearly displayed by the HTXRD technique. They are different for the two precursors, except the formation of amorphous zirconia at low temperature (200 °C) and crystalline zirconia at about 390 °C. Three modifications of Zr(OH)2(NO3)2·H2O (α,β,γ) were identified. Their X-ray powder diffraction patterns were indexed by the successive dichotomy method. The unit cells are triclinic and present some parametric and volumetric similarities from each other and also with that of their precursor. Moreover, the thermal decomposition sequences of Zr(OH)2(NO3)2·(4+x)H2O and α-Zr(OH)2(NO3)2·(1+x)H2O include the formation of anhydrous oxide nitrate ZrO(NO3)2 and anhydrous hydroxide nitrate Zr(OH)2(NO3)2, respectively.

Observed and calculated X-ray powder diffraction data are given for the mineral beryllonite, NaBePO4, from Stoneham, Maine, U.S.A. Diffractometer data taken with CoKα1 radiation and Guinier film data registered with CuKα1 radiation are compared. Two independent procedures were employed to index the patterns.

The crystal structure of α-CoSO4 has been refined by the Rietveld method from X-ray powder diffraction data. The structure is orthorhombic, space group Pnma, a = 8.6127(4), b = 6.7058(3), c = 4.7399(2) Å, V = 273.75(3) Å3. Final RB = 2.41%, RP = 5.24%, RWP=6.66%, RWP (expected) =5.74% (WP =weighted profile). The structure consists of edge-sharing octahedral chains parallel to [010] interconnected by SO4 tetrahedra.

Ceric caesium nitrate CeCs2(NO3)6 and ceric rubidium nitrate CeRb2(NO3)6 have been investigated by means of X-ray powder diffraction. Precise data collected with strictly monochromatic radiation (CuKα1) are reported. Monoclinic unit cell dimensions were found by the indexing program DICVOL91 based on the variation of parameters by successive dichotomy. The final refined parameters are: a = 13.5373(7) Å, b = 7.0787(5) Å, c = 8.1672(5) Å, β = 90.813(5)° for the caesium compound and a = 13.0567(5) Å, b = 6.8684(2) Å, c = 8.1786(3) Å, β = 91.436(4)° for the rubidium compound, and the indexings are characterized by the figure of merit F30 equivalent to 245 (0.0033,37) and 194 (0.0040,39), respectively.

A new high temperature form of Y2O3 has been synthesized at 2220 °C by a laser beam heating technique. The new form has a face-centered cubic structure with a = 5.2644(3)Å, Z = 2, Dx = 5.14 g/cm3, and is considered to have a fluorite-type structure containing disordered oxygen vacancies.

Schlippe's salt (sodium thioantimonate nonahydrate—Na3SbS4·9H2O) has been investigated by means of X-ray powder diffraction at room temperature. The indexed X-ray powder diffraction data are presented.

The title compound was synthesized by high temperature reaction of the component elements. This phase, formerly classified in the group of Nowotny phases, crystallizes in the hexagonal system with space group P63/mcm. Crystal data and indexed X-ray powder diffraction data are reported.