Standardized X-ray powder diffraction data for orthorhombic LaCo0.4Fe0.6O3 prepared by calcination of a glycine-nitrate combustion-synthesized precursor are reported. Orthorhombic unit cell parameters: a = 5.4688 (2), b = 5.5100 (2), c = 7.7462 (3) Å. The reference intensity ratio, I/Icor,= 6.12.

Indexed powder diffraction patterns and related crystallographic data are reported for tetracycline-urea tetrahydrate and tetracycline hexahydrate, neither of which is represented in the X-ray Powder Diffraction File. Objective evaluation of the data indicates high precision of d-spacings and unit-cell parameters, intensities that are acceptably reproducible, sensitivity for low intensity reflections, good resolution of closely spaced reflections, and close correspondence with calculated patterns.

Lattice thermal expansion of a number of compositions in the tetragonal (P4mm) single cell region of the lead zirconate titanate Pb(ZrxTi1−x)O3 system have been measured by high temperature X-ray diffraction. Polynomial coefficients which describe the temperature dependence of the lattice constants of each composition below and above the ferroelectric-paraelectric transition temperature are given.

The lattice parameters of triammonium citrate, (NH4)3C6H5O7, were determined by X-ray single crystal and powder diffraction methods. The crystal structure is orthorhombic with a = 6.187 ± 0.001 Å, b = 14.803 ± 0.004 Å, and c = 10.826 ± 0.003 Å, and from the systematic absences, the space group is Pcc2 ().

The crystalline structure of the M2CuWO6 phases with M = Ba or Sr was obtained from X-ray powder diffraction at room temperature with CuKα radiation. The phases are isostructural with tetragonal unit cells, space group I4/m and Z = 2. The parameters for the Sr2CuWO6 phase are: Mr = 518.6, a = 5.42693(5) Å, c = 8.4087(1) Å, V = 247.65(1) Å3, Dx = 6.954 Mg/m3, μ = 77.75 mm−1, F(000) = 454, R = 0.0375 for 24 reflections; the parameters for the Ba2CuWO6 phase are: Mr = 618.1, a = 5.56392(8) Å, c = 8.6274(1) Å, V = 267.08(1) Å3, Dx = 7.683 Mg/m3, μ = 157.0 mm−1, F(000) = 526, R = 0.0506 for 27 reflections. Cell parameters were obtained from Rietveld refinement. The crystalline structure is based on the perovskite structure. It is laminar with ordered alternating WO6 deformed octahedra and CuO2 planar squares along the [110] direction, joined by corners and rotated perpendicular to the [001] direction. The samples are electrica insulators.

Estimation of reference intensity ratios (ki or RIR) can be made on the basis of an atomic scattering function. Tests of regression equations for 50 compounds that predict an approximate reference intensity ratio from the easily computed scattering function have shown usefulness in multicomponent semiquantitative X-ray diffraction analysis. The method is best applied whenever only one or two minor components of a multicomponent sample have no readily measurable or calculable ki values and must be estimated. Where the difference between observed and predicted constants is large, these tests show that the ratios of true- to test-weight fractions are proportional to the corresponding ki ratios. The largest absolute errors occur whenever the ki must be predicted for components with medium weight fraction values. Estimation of ki for components of less than 10 weight percent results in only small errors in both predicted component and the other components of the sample. Where more than two components require predicted ki in a given sample, unacceptable errors for all components may result.

Line profiles of a powder diffraction pattern and the aberrations which affect the centroid and the variances of the peaks have been analyzed using the visualization in scientific computing (ViSC) systems. The constrained optimization of those aberrations has been derived from the theory developed by Wilson (1963). It allows the determination of systematic instrumental effects and gives indication of other diffraction effects related to the samples. The CuKβ radiation was used to process the experimental data directly as it is comprised of only one single wavelength.

Bafertisite, Ba(Fe, Mn)2Ti(Si2O7)O(OH, Cl)2, has been reported as belonging to three space groups, i.e., Pmmn, P21/m, and Cm. The samples of bafertisite from the original locality Bayan Obo, Inner Mongolia, and from Jiangsu Province, China, were reinvestigated by X-ray methods. On the basis of single-crystal photographs, Pmmn could be ruled out and the relationship between a subcell in P21/m and the true cell in Cm deduced. The transformation matrix from the subcell to the true cell is 002/02¯0/101¯. Using the X-ray powder data, the refined true unit cell parameters in space group Cm are: a=10.612(3), b=13.637(7), c=12.464(2) Å, β=119.49(2)° for Bayan Obo sample, and a=10.633(6), b=13.67(1), c=12.465(5) Å, β=119.55(4)° for the Jiangsu sample. The 00l-reflections, which are rather prominent due to preferred orientation, can only be explained by our new unit cell.

Ba0.5+x/2Zr2P3−xSixO12 or BaZPS compounds were synthesized by the sintering of powders formed by a solid-state reaction. The cell parameters of Ba0.5Zr2P3O12 and Ba0.5875Zr2P2.825Si0.175O12 were determined from X-ray diffraction (XRD) data based on the (#148) space group with hexagonal setting. The cell parameters were found to increase with increasing Si content in BaZPS.

As part of a study by high-resolution X-ray diffraction of chrome ores from the Great Dyke, Zimbabwe, powder data are reported for a well-crystallized ferroan magnesiochromite spinel, in which some Cr had been replaced by Al. Data were obtained by using CuKα1 radiation, with an incident beam focusing monochromator to eliminate the Kα2 component. The cell parameter is a0=8.3123(2) Å, the figures of merit are M17=383 and F17=182 (0.0055, 17) and the calculated density is 4.50(5) Mgm−3. A small amount of sample broadening was observed and this was attributed to a mean crystallite size of 259(1) nm. © 1997 International Center for Diffraction Data.

An iterative external standard method of X-ray diffraction is presented to overcome the difficulties of preferred orientation and peak overlap encountered in quantitative phase analysis. Instead of using only a single line intensity in the traditional external standard technique, all the reflection data are used in the calculation. The accuracy and applicability of this method was tested on a series of two-phase powder mixtures with known composition. The results show markedly good agreement with the actual values. As an example, the analysis was applied to the data collected from an as plated electrodeposited Zn-Fe coating. The determined phase composition of the coating was found to be 88.2 +/− 5.3 wt % δ-phase and 11.8 +/− 0.7 wt % η -phase.

X-ray powder data and crystal data for acetaminophen, C8H9NO2, are reported and results are compared to existing PDF patterns.