The double hydroxide of Li+ and Al3+ is an anionic clay comprising positively charged metal hydroxide layers and intercalated anions. While the structure of the iono-covalently bonded metal hydroxide layer is well known, relatively less knowledge is available regarding the manner in which the anions and water molecules are packed in the interlayer region. The sulfate ion is of special interest as it can potentially intercalate in a multiplicity of orientations and grow an extended hydration sphere. The sulfate-intercalated double hydroxide was synthesized by the imbibition of Li2SO4 into both the gibbsite and bayerite forms of Al(OH)3 to obtain layered double hydroxides with the nominal formula Li2Al4(OH)12SO4·nH2O (n = 4–8). The as-prepared compounds were poorly ordered and did not yield any structural information. Temperature-induced partial dehydration yielded ordered phases of different structures in the two systems. Simulation of the powder patterns of different model structures, followed by structure refinement in both direct and reciprocal spaces, showed that the gibbsite-derived phase yielded a two-layer polytype of hexagonal symmetry (space group P63/m). The local symmetry of the sulfate ion was close to D2d with one of the C2 axes of the SO42− being nearly parallel to the c axis of the crystal. The bayerite-derived phase yielded a one-layer polytype of monoclinic symmetry (space group C2/m). The sulfate ion was oriented with its C3 axes tilted away from the stacking direction. Cooling and rehydration (relative humidity ~70%) resulted in a reversible expansion of the basal spacing due to the ingress of water molecules from the ambient humidity into the interlayer region. Hydration in both cases resulted in turbostratic disorder. The disorder in the bayerite-derived phase was a result of random intergrowth of motifs with rhombohedral and monoclinic symmetries.

Ag3O was synthesized by jet-milling magnetron-sputtered Ag–Ag2O thin films. Heating the jet-milled powders in air and N2 from 40 to 148 °C at ambient pressure produced Ag3O-rich powders. The phase composition and unit-cell parameters of the jet-milled powders were measured as a function of temperature with in situ X-ray powder diffraction experiments from −186 to 293 °C. Ag3O was also produced by ball milling and sonicating jet-milled films at ambient conditions. The phase composition, unit-cell parameters, and thermal-reaction rates indicate nonstoichiometric Ag3O was produced from the reaction of metastable, nonstoichiometric Ag2O (cuprite structure) and ccp Ag. The thermal expansion of Ag3O is anisotropic; below 25 °C, the a-axis expansion is about twice the c-axis expansion resulting in a negative slope of c/a(T). The reversal of the sign of c/a(T) near 25 °C is dramatic. The thermal reaction is arrested when the temperature is rapidly increased from ambient to 130 °C. Ag3O is metastable and decreases its unit-cell volume during kinetic decomposition to Ag when heated above ambient temperature in air and nitrogen. The relative volume expansion of Ag3O is about 80% less than Ag at room temperature and below. The suite of nonstoichiometric Ag3O produced by heating displays a linear relation between c/a and unit-cell volume at room temperature. The c/a and unit-cell volume of a hydrothermally grown Ag3O single crystal reported in a published structure determination was the Ag-rich, low-volume end member of the linear series. The c/a and unit-cell volume are sensitive indicators of the oxygen content and state of disorder.

In this paper, grandite core with Grs64±1Adr36±1Sps2 composition was crystallographically studied. This core represents zone A of the macroscopically visible five A–E zones of the optically anisotropic Grs58–64Adr36–42Sps2 grandite. The applied procedure includes the detailed analysis of the powder diffraction patterns, and the Rietveld refinements of the crystal structures in a series of 18 space groups and two mixtures, which were followed by the comparative analysis of the R-values, site occupancy factors, and the bond lengths and angles. Synthesis of all of the presented results allows us to undoubtedly conclude that studied grandite is not cubic, neither as monophase nor as multiple phases in a mixture. Namely, it was established that structural dissymmetrization occurred and that it crystallized in the disordered rhombohedral $R\bar{3}c$ or orthorhombic Fddd space groups, whereby the first one is more probable. Beside the established lower symmetry of the studied grandite, which could be treated as the primary cause, the residual strain is also not excluded as the second possible cause for its slight optical anisotropy.

Early Copper Age pottery sherds discovered in a cave within the crystalline dolomites of the Southern Carpathians (Romania) were investigated by polarized light optical microscopy (OM), X-ray powder diffraction (XRPD) and electron microprobe analysis (EMPA) to obtain information on the pottery production in the Copper Age in the territory of present-day Romania. Microscopically, the clayey matrix of the ceramic body is highly birefringent or consists of low-birefringent and isotropic parts mixed together, containing fragments of quartz, muscovite, alkali feldspar, plagioclase, biotite, chlorite, heavy minerals and metamorphic and magmatic rocks, as well as an opaque material. The EMPA data revealed an Fe-rich illite-like matrix and helped to identify the mineral nature of the inclusions. Local pottery production in bonfires or surface clamps is envisaged. Miocene illitic clays may have been used as raw materials, mixed with a small amount of sandy temper. The thermal changes revealed by OM, the modification of the XRPD peaks and the EMPA data suggest firing temperatures of between 800 and 850°C.

Second-century CE (common era) household pottery sherds found in the city of Napoca (present day Cluj-Napoca, Romania) in Roman Dacia were investigated by polarized light optical microscopy, X-ray powder diffraction, Fourier-transform infrared spectroscopy and cold field emission scanning electron microscopy coupled with energy-dispersive X-ray spectroscopy to obtain information on technology, raw materials and site of production. Compositionally, all samples are similar with comparable fine and semi-fine microstructures and oriented microtextures. Optically, there is a gradual transition from microcrystalline to an amorphous illitic-muscovitic matrix. The small aplastic inclusions are mostly quartz and feldspar. Fine-grained carbonate aggregates are distributed inhomogeneously in the ceramic body. Well-preserved Middle Miocene foraminifera tests are characteristic of the ceramics. The gradual thermal changes of the matrix and the newly formed phases upon firing, such as ‘ceramic melilite’, Fe-gehlenite, clinopyroxene, glass, hematite and some maghemite support inferences regarding the technological constraints in producing the pottery. The firing took place in a mostly oxidizing atmosphere and the temperature extended from at least 850°C to >900°C. The Middle Miocene marly clay from the area surrounding the site shows similar mineralogical and micropalaeontological contents to those of the ceramic specimens and is the best candidate for the raw material used for local production of the Roman pottery.

The new ternary compound of Al2Cu3Gd was prepared by melting with stoichiometric composition in an electric arc furnace. The X-ray powder diffraction data of Al2Cu3Gd have been collected by the Rigaku Smart Lab X-ray powder diffractometer. The Rietveld refinement method had been used to study the crystal structure of Al2Cu3Gd. The results showed that the Al2Cu3Gd, new compound have the hexagonal structure, space group P6/mmm (No. 191) with a = 5.1822 (1) Å, c = 4.1566 (1) Å, V = 96.67 Å3, Z = 1, and the density is 6.62 g cm−3, and the intensity ratio reference intensity ratio is 1.29.

Powder diffraction data are presented for Ivabradine hydrochloride (pure and solvated forms), a drug marketed worldwide for symptomatic treatment of angina pectoris and inappropriate sinus tachycardia. [Ivrabradine: 3-[3-({[(7S)-3,4-dimethoxy bicyclo[4.2.0]octa-1,3,5-trien-7-yl]methyl}(methyl)amino)propyl]-7,8-dimethoxy-2,3,4,5-tetrahydro-1H-3-benzazepin-2-one]. Many are the different (polymorphic or solvated) phases claimed in the scientific or forensic literature. We have here prepared monophasic samples of six different ivabradine hydrochloride species. Exposure to water vapours, at room temperature, of the anhydrous δ-d form generated pure powders of the tetrahydrate form (the β-form). Two different anhydrous forms (β-d and α) were prepared by gentle, or extensive, heating of the β and δ-d forms, respectively. Acetonitrile and acetone solvates (hereafter called δ1- and δ2-forms) were obtained by precipitation methods from concentrated solutions. Diffraction data were collected on laboratory equipment with Ni-filtered CuKα radiation; cell parameters and space groups were determined from ab initio indexing procedures using the SVD algorithm.

The structure of [Al2(pydc)2(μ2-OH)2(H2O)2]n(pydc = 2,5-pyridinedicarboxylate) was successfully determined from powder X-ray diffraction data. The compound crystallizes in the triclinic system (space group P -1) with a = 6.7813(1) Å, b = 7.4944(1) Å, c = 8.5013(1) Å, α = 95.256(1)°, β = 102.478(1)°, γ = 108.979(1)°. The structure consists of aluminum ions coordinating N and O in distorted octahedra, sharing an edge through two hydroxide ions. These dinuclear complexes are connected by pydc ions, which at one end coordinate by nitrogen and oxygen and only by oxygen at the other end. The pydc orientation is reversed in the neighboring pydc, forming double stranded chains interconnected by the aluminum dinuclear complexes in a ladder-like arrangement along [001].

New salts of barium with dicarboxylic acids (glutaric, adipic, pimelic, suberic, sebacic, and dodecanedioic) were synthesized and characterized by powder diffraction techniques. In addition to the basic crystallographic data and chemical analyses of barium glutarate hexahydrate {1}, barium adipate {2}, barium pimelate {3}, barium disuberate {4}, barium sebacate {5}, and barium dodecanedioate {6}, the processes of their thermal decomposition were investigated by XRPD. All the compounds decompose to barium carbonate at temperatures between 400 and 500 °C.

The compound NH4Fe[Fe(CN)6]·xH2O—a commercially available “Prussian blue” pigment—crystallizes in the Fm3m space group, a=10.232(1) Å, based on X-ray powder diffraction (XRPD) data. XRPD investigations of other commercially available “Prussian blue” pigments and oil paints were undertaken. Results for the pigments showed that the XRPD techniques were able to differentiate several different Prussian blue phases that differed only slightly in chemical compositions. Results for the oil paints allowed for the determination of the major crystalline phases used as fillers. However, on the basis of XRPD investigations of oil paints prepared in our laboratory containing a mixture of true Prussian blue Fe4[Fe(CN)6]3·14H2O and BaSO4 (a common filler), the pigment was detectable only in concentrations higher than 2%. This result suggests that XRPD may not be a preferred technique for the identification of Prussian blue in paintings and other works of art because the concentration of this pigment in such materials is commonly less than 2%.