Precise X-ray powder diffraction patterns for the tetragonal form of Li3B5O8(OH)2 were obtained using a Huber camera; photographs were taken at 22 °C with CuKα1 radiation (λ =1.5406 Å) and with Si as internal standard (a = 5.4308 Å). Refinements of indexed reflections yielded the following parameters: a = 6.8455(4)Å, c = 14.551(1)Å, space group P41212, Z = 4, Dx = 2.31, and Dm = 2.28 g/cm3. The Smith–Snyder figure of merit of F30 = 97(O.OO7,45) compares to that of F30 = 2.6(0.206,57) reported for the existing pattern in the Powder Diffraction File (34-1070).

Indexed X-ray powder diffraction data and crystal data are reported for: synthetic pargasite (P: NaCa2Mg4AlSi6Al2O22(OH)2), fluor-pargasite (FP: NaCa2Mg4AlSi6Al2O22F2), scandian pargasite (SP: NaCa2Mg4.4Sc0.6Si6Al2O22(OH)2) and scandian fluor-pargasite (SFP: NaCa2Mg4.2Sc0.8Si6Al2O22F2).

A rapid whole-pattern profile-matching procedure for the quantitative assessment of multiphase powder diffraction patterns is described. Using a position-sensitive detector, with fixed beam-sample-detector geometry, we report on the efficacy and speed of this method in the quantitative assessment of four different multiphase samples.

Ammonium manganese phosphate monohydrate (NH4MnPO4.H2O) has been investigated by means of X-ray powder diffraction. The title compound is orthorhombic with unit-cell parameters a=5.7289(11), b=8.8167 (12), and c=4.9098 (8) Å.

Two new solubility-limiting phases relevant to nuclear waste disposal are reported, namely CeSiO4 and Ca2Ce8(SiO4)O2, produced by hydrothermal synthesis at 180 °C. X-ray diffraction data are presented for both compounds. Rietveld refinement was performed for each of these phases. CeSiO4 was confirmed to be a zircon structure type, with space group I41/amd, unit celltype="bold">abold=6.9564(3),type="bold">cbold=6.1953(4) Å. Bond lengths for SiO4 are in excellent agreement with published values; Ce4+ is coordinated to eight oxygen atoms with four regular and four short bonds. Ca2Ce8(SiO4)O2 was shown to have an apatite structure, with space group P63/m and unit celltype="bold">abold=9.4343(3),type="bold">cbold=6.8885(4) Å. The unit cell and bond lengths were found to be slightly smaller than would be expected from other lanthanide-containing analogs; possible reasons for this are discussed.

X-ray powder diffraction pattern for InN synthesized using a microwave plasma source of nitrogen is reported. The data were obtained with the help of an automated Bragg-Brentano diffractometer using Ni-filtered CuKα radiation. The lattice parameters for the wurtzite-type unit cell are ao=3.5378(1) Å, co=5.7033(1) Å. The calculated density is 6.921±0.002 g/cm3.

The compounds BaR2O4, (R = Pr, Tb), where R are two of the less frequent trivalent lanthanides, have been prepared under reducing atmosphere from mixtures of BaO2, the R metals, and the oxides Pr2O3 and Tb4O7, respectively. The crystal structure of BaR2O4 have been refined from X-ray powder diffraction data by the Rietveld method of profile analysis using 31 parameters in each case. Both oxides are orthorhombic, isotypic with SrY2O4, of the perovskite-related CaFe2O4 structure type, S.G. Pnma (No. 62), Z = 4, a = 10.6113(8), b = 3.6303(3), c = 12.485(1) Å, and V = 480.93(5) Å3 for R = Pr; and a = 10.4282(8), b = 3.4893(3), c = 12.1809(6) Å, and V = 443.22(3) Å3 for R = Tb. The R–O distances vary between 2.15(6) to 3.40(6) Å for R = Pr, and between 2.15(3) to 2.91(5) Å for R = Tb.

Palladium tetrammine dichromate, [Pd(NH3)4]Cr2O7, was obtained by precipitation from [Pd(NH3)4]Cl2·H2O and (NH4)2Cr2O7. The X-ray diffraction pattern of this compound corresponds to a new phase, which was indexed in the triclinic system, but on a cell that should be considered as preliminary. From the chemical analysis and the X-ray absorption experiments at both K-edges of Pd and Cr, we conclude that the surrounding of these atoms is kept during formation.

Gamma-phase lithium aluminate (LiAlO2) is a ceramic powder used in molten carbonate fuel cells (MCFCs) and in other nuclear and ceramic applications. Upon exposure to water vapor and carbon dioxide at 25 °C, we have observed that gamma-LiAlO2 converts to lithium aluminum carbonate hydroxide hydrate, Li2Al4(CO3)(OH)12·3H2O(LACHH) and Li2CO3. The conversion was observed by X-ray diffraction (XRD) and carbonate analysis. An equation for the conversion is given, and the morphology is determined by scanning electron microscopy. A high-temperature XRD study and thermogravimetric/differential thermal analysis (TGA/DTA) showed that LACHH decomposes at 250 °C. The decomposition products of LACHH and Li2CO3 react to form first alpha-LiAlO2 and then gamma-LiAlO2 at temperatures of 650 and 1000 °C, respectively.

Ba2NaNb5,O15 and eighteen additional compositions in the NaNbO3-BaNb2O6 system from 60 to 85 mole % BaNb2O6 have been prepared and studied by X-ray powder diffraction. A calculated pattern has been used to aid in indexing the powder pattern of stoichiometric Ba2NaNb5O15(BNN-S). The lattice parameters of BNN-S have been determined from repeated measurements of 2 higher order reflections and are a=b=17.5994(8)Å and c=7.9771(9)Å. A comparison with the Powder Diffraction File (PDF) 34-210 indicates that the present data provide a more precise match to the unit cell, include additional weak reflections and cover a greater 2θ range. There is a tungsten bronzetype solid solution range from 60 to 75 mole % BaNb2O6.

X-Ray powder diffraction data and unit cell parameters of industrially produced, as well as bench scale prepared, ammonium paratungstate tetrahydrate are reported and compared with current Powder Data File (PDF) (1989) patterns. A least-squares refinement resulted in two slightly different unit cells. Both cells are monoclinic with S.G. = P21/n(14), Z = 2. The density, 4.639(2)kg/m3, calculated from one of these unit cells corresponds reasonably well with a measured value of 4.61 (2). It has, however, not been possible to determine at present why ammonium paratungstate tetrahydrate has two unit cells. No relation between the crystalline form and the method of preparation nor the exact water content could be established.