This study attempted to quantify the interstratificational broadening of the randomly interstratified illite/smectite (random I∕S) basal reflection and to evaluate the percentage of the interstratified illite layers (%I) from the result. The interstratificational broadening was quantified using the distributional discrepancy (D) defined as D=[∑t∣ft(obs)−ft(ref)∣]∕2, where ft(obs) is the frequency of a crystallite containing thickness, t (the number of layers), measured from a basal reflection broadened by interstratifications, and ft(ref) is the frequency for a basal reflection with no interstratificational broadening. The basal reflections at 5.2° 2θ under glycolation and 8.84° 2θ under thermal dehydration provided the ft(obs) and ft(ref) of random I∕S. The linear relation, D=2.17%I+2.49(0⩽%I⩽30), was obtained from simulations for SWy-2 (Wyoming, USA).

This paper describes a straightforward method for the identification of the Miller indices associated with the face of a crystal of low symmetry. The method relies on orienting a crystal face parallel to the sample holder in the goniometer of a powder diffractometer. An intense diffractogram resulting from a single family of lattice planes parallel to the crystal face is obtained. The application of silicon powder to the surface of the crystal provides a means to correct 2Θ values for any misalignment of the crystal face. Calculated 2Θ and intensity values are used to assign the reflections from the corrected single-crystal diffractogram to a particular set of related lattice planes. In this paper are listed the corrected experimental 2Θ and intensity values for a particular face of a large single crystal of monoclinic hydroxylapatite and the theoretical 2Θ and intensity values for the h00 set of planes. Comparison of these parameters leads to the unambiguous assignment of that particular crystal face to the h00 Miller index.

Florencite-(Nd) [(Nd,Ce)Al3(PO4)2(OH)6], was first described by Milton and Bastron (1971) from fracture surfaces in weathered cherts of the Franciscan Complex, south of Sausalito in Marin County, California. Florencite-(Nd) occurred there as a moderate-brown pulverulent earthy material; individual crystals were not discernible under microscopic examination. A semi-quantitative spectrographic analysis showed the presence of Nd (3 wt. %) and Ce (0.5 wt. %). No powder data for florencite-(Nd) exists in the current powder diffraction file.

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.

The ferroelectric liquid crystal material [4-[(4-methyloxyfenyl) carbonyloxyl] bifenyl-4′-yl]-(S)-2-methylbutoxypropionate containing a lateral methyl group on the aromatic ring of the alkoxybenzoate unit and two chiral carbons has been investigated by X-ray powder diffraction analysis at the 28 °C–105 °C temperature range. On cooling through the SmC temperature range, the layer spacing decreases from 28.3 to 27.7 Å with a small variation of average intermolecular distances. Lattice parameters of tetragonal and monoclinic crystalline phases occurring at lower temperatures have been determined.

The present paper establishes that the ratio between the XRD pulse counts of cement clinkers at d=0.278 and 0.274 nm bears a distinct relationship with the degree of sintering of the clinker, which is one of the factors that determine the cement quality. The paper also presents a rapid and accurate method for predicting both 3- and 28-day compressive strength (CCS) of cement mortar cubes based on XRD of the cement clinkers. The method is based on an index Xn derived from the XRD pulse counts at d=0.2959 and 0.287 nm corresponding to alite (hkl=202) and belite (hkl=102) phases of the clinker, respectively. The regression equation derived for a particular plant is (1) 3 day CCS=Xn×240 kg/cm2, when Xn<1 and 240+26 (Xn−1) kg/cm2, when Xn>1, where Xnmaximum=5.5. (2) 28 day CCS=C+C×In/100, where C=3 days CCS estimated by XRD (1), In=90−10Xn, where Xnmax=5.5. Calculated CCS values, in average, vary from the conventional test values by +5.9% to −5.4% and +3.8% to −3.5% in cases of 3- and 28-day CCS, respectively.

The X-ray powder diffraction pattern for the title compound is reported in the range 5 ≤ 2θ ≤ 125°. The sample was prepared through solid-state reaction of BaCO3, CuO, and Pr6O11, and characterized with respect to oxygen content through iodometric titration. Refined parameters for the orthorhombic (space group Pmmm) unit cell are a = 3.8587(2) Å; b = 3.9302(1) Å; c= 11.7126(3) Å; a/b = 0.98181(6); a/c = 0.32945(2); b/c = 0.33555(1); Z = 1; Dx = 6.705(2) Mg m−3; V = 177.62(1) Å3; formula wt. = 717.48(16) g mol−1; SS/FOM: F30 = 48(0.005,127).

Methods of chemical preparation and crystallographic data are reported for four new condensed phosphates: one hydrated cyclotriphosphate MnAg4(P3O9)2·6H2O and three long-chain polyphosphates: MnAg2(PO3)4, NiAg4(PO3)6 and NiNa4(PO3)6. Two of these new condensed phosphates, associated with manganese, belong to previously investigated structure types.

Quantitative phase analysis is one of the major applications of X-ray powder diffraction. The essential principle of quantitative phase analysis is that the diffraction intensity of a component phase in a mixture is proportional to its abundance. Nevertheless, the diffraction intensities of the component phases cannot be compared with each other directly since the coherent scattering power per unit cell (or chemical formula) of each component phase is usually different. The coherent scattering power per unit cell of a crystal is well represented by the sum of the squared structure factors, which cannot be calculated directly when the crystal structure data is unavailable. Presented here is a way to approximate the coherent scattering power per unit cell based solely on the unit cell parameters and the chemical contents. This approximation is useful when the atomic coordinates for one or more of the phases in a sample are unavailable. An assessment of the accuracy of the approximation is presented. This assessment indicates that the approximation will likely be within 10% when X-ray powder diffraction data is collected over a sufficient portion of the measurable pattern.

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.

The crystallite size distribution is an important parameter affecting the processing and properties of materials or products containing crystallites. The X-ray diffraction pattern collected with a two-dimensional detector may contain one or several spotty diffraction rings when an appropriate X-ray beam size is used. The spottiness of the diffraction ring is related to the size, size distribution, and orientation distribution of the crystallites. The intensity of a diffraction spot may represent its volume or size of a crystallite when a perfect Bragg condition is met. This paper introduces the algorithms and procedure to evaluate crystallite size distribution from a 2D diffraction pattern by rocking scan.

Crystal structure analyses by the Rietveld method have shown that the framework structures of zeolites ZSM-5 and ZSM-8 are essentially identical. Therefore, it is difficult to distinguish the two phases especially when the template-free H forms are studied. In addition, some inconsistencies in publications on the two zeolites aggravate the correct interpretation of the powder diagrams. A powder pattern published for ZSM-8 which indicates significant differences between the lattice constants of ZSM-8 and ZSM-5 is shown to be incorrectly indexed. Correct reindexing gives lattice constants for ZSM-8 matching average ZSM-5 values. Peak splitting of a ZSM-8 reflection at 2θ≈23° (CuKα) has been used frequently to distinguish ZSM-8 from ZSM-5. However, it is also a common feature of ZSM-5 diagrams when the difference between a and b lattice constants is big enough to separate hkl and khl reflections within the instrumental resolution. Our data on two ZSM-8 samples indicate that cell dimensions of ZSM-8 do not deviate from average ZSM-5 values. It is suspected that effects in the decomposition of crystals upon calcination, and/or morphology and shape of twin individuals, and/or stacking faults account for different sorption properties of the two zeolites rather than differences in their average crystal structures.

The crystal structure of pomalidomide Form I has been solved and refined using synchrotron X-ray powder diffraction data and optimized using density functional theory techniques. Pomalidomide Form I crystallizes in the space group P-1 (#2) with a = 7.04742(9), b = 7.89103(27), c = 11.3106(6) Å, α = 73.2499(13), β = 80.9198(9), γ = 88.5969(6)°, V = 594.618(8) Å3, and Z = 2. The crystal structure is characterized by the parallel stacking of planes parallel to the bc-plane. Hydrogen bonds link the molecules into double layers also parallel to the bc-plane. Each of the amine hydrogen atoms acts as a donor to a carbonyl group in an N–H⋯O hydrogen bond, but only two of the four carbonyl groups act as acceptors in such hydrogen bonds. Other carbonyl groups participate in C–H⋯O hydrogen bonds. The powder pattern has been submitted to ICDD® for inclusion in the Powder Diffraction File™ (PDF®).

The title compound was identified as the major phase in a corrosion deposit by indexing its powder pattern, and locating an isostructural vanadium(II) compound in the NIST Crystal Data Identification File. The identity of the compound was confirmed by a Rietveld refinement. Hexaaquairon(II) trifluoromethanesulfonate crystallizes in the monoclinic space group C2/m, with a=18.6415(14), b=6.9291(5), c=6.5938(5) Å, β=104.742(6)°, V=823.68(10) Å3, and Z=2. The structure consists of alternating layers of octahedral hexaaquairon(II) cations and triflate anions. The cations and anions are linked into layers parallel to the bc plane by hydrogen bonds. Each water molecule donates two protons to sulfonate oxygens, and each sulfonate oxygen acts as an acceptor of two protons. A reference powder diffraction pattern is reported.

The effects of sample transparency in a powder diffraction experiment are discussed, and formulas including effects from horizontal divergence are derived. It is shown that the classical formula by Alexander [L. E. Alexander J. Appl. Phys. 21, 126 (1950)] is only a limiting case for zero horizontal divergence. It is also shown that in some cases extinction effects can play a role. The impact of these effects on both the line profile as well as the integrated intensity and experiments illustrating these phenomena, are discussed.

The room temperature powder pattern of lapatinib ditosylate monohydrate (active ingredient in Tykerb used to treat refractory breast cancer) was indexed and the cell from the single crystal X-ray diffraction structure was refined using the experimental capillary data. Unit-cell parameters for the orthorhombic compound with space group Pbca refined from powder diffraction data are a=9.6850±0.0009 Å, b=29.364±0.003 Å, and c=30.733±0.003 Å, α=β=γ=90°, z=8, V=8740.1 Å3. Values of 2θ, d, I, and Miller indices are reported.

Samples of the superconducting compound (Hg,Re)–1223 of nominal composition Hg0.82Re0.18Ba2Ca2Cu3O8+δ and different oxygen contents were studied using X-ray absorption and diffraction techniques. In the synthesis process, treatments under different ratio oxygen/argon gas mixtures of 5%, 10%, and 15% O2 resulted in samples named as Sample A, Sample B, and Sample C, respectively. It was determined by using the XANES technique that in these compounds the Re cation has valence +7. The study by EXAFS determined that the octahedral coordination is distorted and the distances of Re–O bonds are of the order of 1.85 A˚ for equatorial oxygen and 2.10 A˚ for the apical ones. The Rietveld refinement of X-ray powder diffraction data revealed that the studied samples presented segregation of two superconducting phases with space group P4/mmm and distinct lattice parameters, also confirmed by anomalous X-ray scattering. The main phase was associated to the phase (Hg,Re)–1223 with higher oxygen content and the secondary superconducting phase was associated with the undoped Hg–1223 phase. Measurements of ac magnetic susceptibility showed that the sample treated under 10% O2 atmosphere presented the best superconducting properties.

The titled compound, Hg2[Fe(CN)5NO], was synthesized and studied by X-ray powder diffraction, infrared spectroscopy, Mössbauer spectroscopy, and atomic force microscopy. The results arising from this study indicate that this compound is anhydrous and crystallizes in the P222 orthorhombic symmetry. The unit cell parameters were quantified as a=16.5905(9) Å, b=12.3145(8) Å, and c=8.7576(5) Å. The measured and calculated density values are Dm=1.149 g/cm3 and Dc=1.145 g/cm3, respectively, with Z=2.