A two-stage procedure is described for quantitative phase analysis of multicomponent mixtures. Profile analysis of the diffraction pattern of a mixture of phases is done in stage one to obtain integrated intensities with higher accuracy. In stage two a structural refinement is done which yields a scale factor. The weight of a phase in a mixture is proportional to its specific scale factor. The two-stage method was found to be effective for the quantitative phase analysis of a mixture of minerals which always contain structural defects. The procedure was tested first by using two artificial mixtures and then it was applied to natural kaolin. The results obtained were more accurate than some of the other methods used for quantitative analysis; moreover, it can also be used with mixtures containing amorphous or undetermined phases.

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Dyke, Zimbabwe, powder data are reported for a well-crystallized ferroan magnesiochromite spinel, in which some Cr had been replaced by Al.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.

A commercially available combined X-ray diffraction – differential scanning calorimetry (XRD-DSC) stage was adapted for studies of gas loading in microporous materials, including metal organic frameworks (MOFs). Insertion of a custom-built humid atmosphere swing chamber (HASC) between a humidity generator and the XRD-DSC stage facilitates both humid atmosphere and vacuum swing gas loading. The HASC is necessary to buffer between the humidity generator and the XRD-DSC stage, allowing the gas mixture to homogenize prior to sample exposure, so that both humid atmosphere and vacuum swings could be performed. The changes in XRD can be used to follow structural changes, including collapse, which is indicative of a lack of microporosity upon activation, and the flexibity of frameworks upon gas sorption–desorption cycles. Measurements of the area under the DSC curve allows for calculation of the isosteric heat of adsorption (Qst; kJ molGAS−1). Vacuum-atmosphere swing experiments performed at different pressure steps allow for the reconstruction of the enthalpy of gas adsorption before and after a phase transition. These modes of operation are illustrated in three case studies from a program of exploratory MOF synthesis used to discover novel materials for selective gas sorption from humid gas streams: (1) gas binding in Stony Brook metal organic framework-1, (2) zeolitic imidazolate framework-7 response to variable pressure vacuum-atmosphere swing, and (3) high throughput evaluation of the selectivity of novel MOFs synthesized from customized linkers.

X-ray fluorescence (XRF) is frequently used to measure layer thickness in the micrometer range. But also X-ray diffraction (XRD) can be used in a comparable way and offers the benefit to differentiate coating layers by their crystal structure. Thus, the thickness of different oxide layers of the same element can be determined, e.g., FeO, Fe3O4, and Fe2O3 on Fe-substrate. An approach for such measurement is discussed. Furthermore, with a suitable sample stage, a spatially resolved coating thickness map can be measured in a nondestructive way. Applications and validations of the presented XRD method for the measurement of the thickness of zinc coatings on steel are given and compared with results from XRF, glow-discharge optical emission spectroscopy, and optical micrographs. In addition, the methodology was tested and validated using XRF reference standards and iron nitride and iron oxide layers.

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 ().

A task group of the JCPDS—International Centre for Diffraction Data (ICDD) was established for the purpose of investigating a methodology which would be applicable for statistical process control monitoring of X-ray powder diffractometers. A procedure for collecting X-ray diffraction data for statistical process control purposes and the incorporation of these data into control charts are presented. The results of this task group show that, through the use of statistical process control methods, noncontrol situations for diffractometers were detected, the causes of these problems were identified, and these problems were corrected and noted on control charts.

An improved backloading method to determine the reference intensity ratios of sedimentary minerals is presented. More than 50 reference intensity ratios of more than ten types of minerals formed in typical sedimentary environments were measured. Quantitative tests were performed on those minerals. Comparison of the results show that this method minimizes preferred orientation and improves quantitative precision (absolute deviation is less than 3%) so that it is an acceptable specimen loading method.

A previously manually operated film comparator used to evaluate Guinier films has been automated as a film scanner of the flat film type. The film movement is controlled by a stepper motor and the intensity of the transmitted light is recorded as a function of position on the film. A personal computer controls the stepper motor and records the measurements of the transmitted light intensity. The data quality is judged from refinements of lattice constants for α-SiO2 and ZrO2. The powder pattern for Pb2Sr2Ho0.625Ca0.375Cu3O8 and a high temperature study of the thermal expansion of GeO2 are presented.

X-ray powder-diffraction data for Pb2(C2O4)(NO3)2·2H2O were obtained. The crystal system was determined to be monoclinic. The unit-cell parameters were refined to a=10.613(2) Å, b=7.947(2) Å, c=6.189(1) Å, and β=104.48(2)°.

This work provides a short summary of techniques for formally-correct handling of statistical uncertainties in Poisson-statistics dominated data, with emphasis on X-ray powder diffraction patterns. Correct assignment of uncertainties for low counts is documented. Further, we describe a technique for adaptively rebinning such data sets to provide more uniform statistics across a pattern with a wide range of count rates, from a few (or no) counts in a background bin to on-peak regions with many counts. This permits better plotting of data and analysis of a smaller number of points in a fitting package, without significant degradation of the information content of the data set. Examples of the effect of this on a diffraction data set are given.

Low energy characteristic X-ray emission from Al2O3 monocrystalline specimens is measured under bombardment of 100 keV Xe+ ions. The electric field influence on emission of the X-rays of constitute elements in the specimens was investigated. The energy dispersive X-ray spectroscopy spectra show that the characteristic X-ray of Al-Kα seems to be depressed by the applied dc voltages, while the peak intensity of O-Kα was not notably influenced. The O-Kα peaks were broadened and the total counts increased as a higher dc bias was applied. It is possible that a dc electric field parallel to the target surface may influence the X-ray emission from it under ion bombardment.

Three orthovanadates ATh2(VO4)3with A = Li, Na, Ag have been synthesized by solid state reaction. Single crystals of AgTh2(VO4)3were obtained. This compound is isotypic with sheelite whose space group is I41/a(88). The two other compounds (A = Li, Na) have a zircon type structure: I41/ amd(141). Unit-cell parameters and powder diffraction data for the three compounds are reported.

X-ray powder diffraction data, unit-cell parameters and space group for a new bis(β-diiminato) Cu(II) complex, C48H62CuN4O4 are reported [a = 13.330 (3) Å, b = 11.137(2) Å, c = 8.832(2) Å, α = 78.88(2), β = 94.73(2), γ = 114.55(2), unit-cell volume V = 1170.26 Å3, Z = 1, and space group P − 1]. All measured lines were indexed and are consistent with the P−1 space group. No detectable impurity was observed.

Characterization of materials used in the digital imaging industry has been performed using micro X-ray diffraction (microXRD) techniques. Case studies are described that demonstrate the use of microXRD for identification of phases, texture, and microstructure morphology of components used in imaging applications.

X-ray powder diffraction analysis of samples obtained by thermal treatment of coprecipitated amorphous xCd(II) (1-x)Ni(II)2Fe(III)-hydroxides reveals that intermediate crystalline spinel species with lattice constants less than those for the nominal composition are formed before the designated cadmium-nickel ferrites, CdxNil-xFe2O4, come into existence.