This paper outlines some features of diffraction instrumental monitoring (DIM), a method which can prove helpful to evaluate systematic effects from diffraction measurements and facilitate the comparison of results. The work provides some consideration of the significance of the information contained in diffraction patterns and the ability of DIM methods to yield the effective values of instrumental parameters obtained under working conditions.

The outcome of the analysis of data from a Round Robin on a KCl sample is reported. The research project has led to a definition of a working protocol for the treatment of X-ray diffraction data from powders (XRPD). The protocol is based on the method of “Diffraction Instrumental Monitoring” (DIM), whose main characteristics are briefly illustrated. When experimental data are referred to the expected standard values of the lattice parameter, the method enables comparison with data obtained from differing instrumentation found in different laboratories. Application of DIM to the KCl Round Robin demonstrates the ability of DIM to effectively evaluate systematic contribution. Accuracy on the cell parameter is obtained as a direct consequence; in this application, where the knowledge of the KCl d-spacing was not a problem, the accuracy of lattice parameter is a feedback for constraining the evaluation of the effective values of the experiment-related parameters.

Polycrystalline lead iodide, PbI2, was recrystallized from hot water to reproducibly obtain flat plate-like crystals, which manifested extreme preferred orientation greatly favoring the 001, 002, 003, and 004 planes. Polycrystalline samples of PbI2 were intercalated with tripropylamine, simultaneously producing a “new” intercalate 001 peak at 7.791°2θ (d=1.1347 nm) and diminishing the host PbI2 001 peak at 12.67°2θ (d=0.6980 nm). This is consistent with large increases in the c direction of the unit cell associated with inserting a guest between adjacent iodide layers of the host PbI2. Experimental powder diffraction results are compared to theoretical values calculated using CRYSTALMAKER and CRYSTALDIFFRACT software

The object was to perform simultaneous quantitative analyses of complex pharmaceutical solid mixtures by the Rietveld method. Mixtures consisting of anhydrous β-carbamazepine, anhydrous α-carbamazepine, and carbamazepine dihydrate were chosen as the model system. Lithium fluoride was used as the internal standard. Mixtures of various compositions were prepared and subjected to X-ray powder diffractometry (XRD). The XRD pattern of each mixture was analyzed by the Rietveld method and at the end of the refinement, the goodness of fit was evaluated. When the analyte concentration was high (≥20%), the relative error in the determination was <±5%. The detection of analyte was possible even when its concentration was low (<1% w/w). A unique advantage of the method is that it enables simultaneous quantitative analyses of multiple phases without the requirement of “standard curves.” © 2001 International Centre for Diffraction Data.

Using a recent proposed analysis procedure for quantitative phase determination by X-ray powder diffraction, YBa2Cu3O7−x solid state formation reaction kinetics at 900 °C was studied. Although there was the presence of partial amorphous components, it was possible to determine a reaction route for the synthesis of the title compound from X-ray powder diffraction data collected at various stages of the thermal treatment and using the Rietveld method for the quantitative determination of the phase composition

LiCu2O2 crystals grown by spontaneous crystallization from the fluxed melt were studied by powder X-ray diffraction. The phase analysis shows that the applied growth conditions are suitable for preparation of a single-phase compound. The as-grown crystals contain only traces of foreign phases (Li2CuO2, CuO, Cu2O) typical for preparation of the LiCu2O2 compound. Attempts to anneal or quench the as-grown crystals led to two-phase samples containing LiCu2O2 and LiCu3O3. X-ray powder diffraction pattern of a LiCu2O2 crystal is reported and compared with literature data. The crystal structure is orthorhombic, space group Pnma, in agreement with literature data. Lattice parameters of the studied sample are a=5.7286(2) Å, b=2.8588(1) Å, and c=12.4143(3) Å. Time evolution of a diffraction pattern illustrates a slow increase of the secondary-phases contribution assumed to be due to interaction of the powdered crystal with humid air. A brief summary of compounds known in the Li–Cu–O system is included

The effects of proper drying and grinding of [Fe(Htrz)3](ClO4)2⋅1.85H2O specimens on the quality of X-ray powder patterns are illustrated (Htrz=1H-1,2,4-Triazole). A procedure is suggested to achieve high-quality, reproducible X-ray powder patterns of the compound. The observed powder diffraction data of the compound are reported together with preliminary indices calculated for a monoclinic system with cell parameters a=15.8160 Å, b=20.6134 Å, c=13.0321 Å, β=103.83° and Volume=4125.633 Å3, with reliability factors: M15=10.4, F15=22.0 (0.0100; 68) and space group P21/m. This compound is very similar to the compound [Cu(Hyetrz)3](ClO4)2⋅3H2O and a comparison is made between the cell parameters of the two compounds

Si–SiC composite (reaction bonded SiC) with a submicron SiC microstructure (starting SiC particle size: 0.22 μm) was examined by XRD analysis to determine the amount and phase composition of the secondary SiC formed by the reaction between silicon and carbon during the sintering process. It was found that the secondary SiC has grown onto the original hexagonal α-SiC grains as well as into the porosity of the green body. An increase of 3C–SiC was found within the microstructure after infiltration (from 2.6 wt. % before infiltration to 8.8 wt. % after infiltration) whereas the 4H-ploytype content was reduced. This behavior may be explained by the very small original SiC grains which acted as seeds for disoriented SiC growth and were assumed to force the nonepitaxically deposition of secondary SiC. Solid state and fast transportation processes caused the observed transformation of the SiC. Examinations of the silicon source (infiltrant) after the infiltration procedure showed that most of the carbon was converted to SiC with cubic modification (3C stacking sequence)

X-ray powder diffraction data for the orthorhombic natural amino acid djenkolic acid, C7H14N2O4S2, is described in this paper. The orthorhombic cell parameters are: a=8.12 Å, b=12.16 Å, and c=5.38 Å

Keeping with tradition, the 2000 MRS annual meeting again took place in Boston Copely Plaza from November 27 to December 1. The 2000 meeting was well organized and well attended, with a total of 4600 attendees representing industrial, academic, and government sectors. The rich technical program was multi-disciplinary (41 symposia) to meet the needs of the attendees. A total of 4000 papers were presented. There were a number of memorable lectures, several special seminars on policy and funding, an award ceremony, a new educational seminar series that focused on the scientific basis and practical application of commercial tools. The meeting also highlighted an elaborate exhibit, poster sessions and other well organized events. This report summarizes various events which took place at the meeting.