X-ray powder diffraction data are presented for nine new phases with the tetragonal tungsten bronze structure. By comparison with the structure of the M=Nb,RE=La analogue, these contain Ba in the large pentagonal sites with coordination number 15, a range of large rare-earth cations and Bi in the twelve coordinate sites, and the smaller cations, Ti and either Nb or Ta, in the octahedral framework sites. The a lattice parameter data of the tetragonal unit cell show an approximately linear variation with trivalent ion radius, apart from Dy, whose value appears to be anomalous; data for c show little variation with trivalent ion radius.

We know a lot about normal values of bond distances, bond angles, torsion angles, and other molecular parameters. This knowledge can be incorporated into the structure solution process and into Rietveld refinement through the use of restraints and rigid bodies. An important measure of the quality of the refined model is the chemical reasonableness of molecular geometry. Refinement of the structures of calcium tartrate tetrahydrate and guaifenesin is used to illustrate the importance of chemical reasonableness in determining the quality of a Rietveld refinement.

Complexes of 1,8-bis(dimethylamino)naphthalene, known also as DMAN, with phthalic acid, terephthalic acid, and 5-aminoisophthalic acid were synthesized and investigated by means of powder diffraction methods. DMAN and phthalic acid complexes crystallize in the orthorhombic system, space group Pnmm (59) with the lattice parameters a=1.17423(3) nm, b=1.7124(4) nm, c=0.9933(4) nm, V=1.997 24 nm3, whereas DMAN complexes with terephthalic acid or 5-aminoisophthalic acid crystallize in the monoclinic system in the space group P2 or P2∕m with the lattice parameters a=2.4337(5) nm, b=0.9665(2) nm, c=1.1800(3) nm, β=91.53(2)°, V=2.774 51 nm3 and a=2.1609(7) nm, b=1.1017(6) nm, c=1.8921(7) nm, β=112.095(34)°, V=4.173 46 nm3, respectively.

X-ray powder diffraction data for N,N'-diphenylguanidinium nitrate, within the temperature range of 103–293 K, are reported. The pattern at 293 K was confirmed by a fitting of the overall parameters performed with FULLPROF using the atomic parameters obtained from single-crystal studies. The compound is orthorhombic, space group Pna21 (33), with unit-cell parameters a=1.7058(4) nm, b=1.3933(3) nm, c=0.5821(1) nm, and V=1.3834(6) nm3. The unit-cell parameters for the other six temperatures measured were determined by performing pattern matching with FULLPROF. The unit-cell volume contracted on cooling from 1.3834(6) nm3 to 1.3403(4) nm3. The thermal expansion tensor was calculated from the changes of the unit-cell parameters with temperature. The elements of the thermal expansion tensor at 293 K are α11=125(4),α22=57(9), and α33=82(3)×10−6 K−1.

Thin-walled heat-shrink poly(ethylene terephthalate) (PET) tubing is reported for use as an alternative for glass and Kapton® capillaries. PET tubing displays properties such as low X-ray absorption and smooth diffraction profiles. The 2.0 mm thin-walled (0.05 mm thick) and 0.5 mm thin-walled (0.02 mm thick) heat-shrink PET capillaries are 86% and 96% transparent to 1.54 Å X-rays. The low X-ray absorption and relatively smooth X-ray scattering profile of PET make it an ideal material for the home laboratory where the long wavelength, low flux, and low brilliance X-ray sources are employed. PET capillaries can be easily cut and manipulated and fixed to copper pins, which in turn can be employed in low-temperature and automated data collection routines.

A study examining the feasibility, and possible necessity, of using transmission data from capillary mounted samples for quantitative analysis of hydrated cement systems was conducted. In order to obtain true quantitative results, the amorphous contents were determined by the addition of an internal standard. The amorphous content of the starting tricalcium silicate was found to be approximately 21–22 wt %, in close agreement with previously published results. The study revealed that the spherical harmonics preferential orientation correction may not be reliable with unmicronized hydrated cement materials in reflection geometry, as chemically unreasonable progressions in Portlandite content with time were observed. The data obtained from capillary measurements, however, exhibited little or no preferential orientation, and appeared to produce the progression of phase contents expected from the reaction. The use of capillaries would appear to be justified in some circumstances to obtain reliable quantitative results from hydrated cementitious materials. In this particular system, a significant fraction of calcium carbonate was present as aragonite, as well as the more usual calcite.

A polycrystalline sample of YbCoO3 was prepared using a water-soluble complex method at relatively low temperatures. Common chelating ligands such as citric acid were employed for the synthesis of complex-based precursors, followed by thermal decomposition of the precursors at high temperatures. X-ray diffraction data were collected and the crystal structure was refined by the Rietveld method. The structure of YbCoO3 can be described as a sesquioxide C-M2O3-like structure with space group Ia-3 and unit-cell parameter a=10.4470 (2). The Yb3+ and the Co3+ cations are found to preferentially occupy the two nonequivalent 8d and 24d sites, respectively. The two independent atoms Yb/Co have octahedral coordination; however, the degrees of distortion of their coordination polyhedron are different. The relationship between the title compound and the orthorhombic Perovskite structure of YbCoO3 reported in the literature is established.

XRD analysis of plasma-vapor-deposited ErT2 films during aging (T decay to 3He) reveals an hkl-dependent unit-cell expansion in which (200) grains expand out-of-plane as much as 0.01 Å more than (111) out-of-plane grains. Texture analysis of an aged ErT2 film reveals a bimodal (111)/(200) out-of-plane preferred orientation. sin2 ψ analysis reveals significant in-plane macro-strain due to 3He bubble formation/growth. The mechanistic origins regarding these observations are also discussed.

A new polymorph of Al2(WO4)3 is observed from in situ high pressure powder X-ray diffraction (ADXRD) measurements at 3.4 GPa. The ADXRD pattern at 3.4 GPa could be explained based on a monoclinic lattice (space group P21) with unit cell parameters: a=9.5884(24), b=12.5204(38), c=7.8463(33) Å, and β=91.98(2)°.

A state-of-art semiconductor technology-based position sensitive area detector, namely D/teX-25, has recently been developed for high-speed and high-sensitivity X-ray diffraction (XRD) analysis of materials. X-ray powder diffraction intensities obtained by a D/teX-25 detector were found to over 50 times higher than those by a conventional scintillation counter. A D/teX-25 detector mounted on a conventional 2 kW XRD system has been used to collect ultrafast XRD data with scanning speeds up to 160°2θ per minute. Ultrahigh-speed XRD is particularly useful for time-resolved dynamical and in-situ studies. A D/teX-25 detector was successfully used on a Rigaku XRD differential scanning calorimetry (DSC) system for simultaneous measurements of XRD and DSC data under controlled temperature and humidity conditions. This has made possible the study of complex and rapid phase transformations of pharmaceutical terfenadine. The D/teX-25 area detector has also been used for recording two-dimensional XRD patterns showing the particle-size effects on α-quartz powder intensities and to obtain digital X-ray topographic images of a complex dislocation network in a Si wafer.

Four aliphatic-aromatic diols with ether linkages [4, 4′-Bis(2-hydroxyethoxy)benzophenone, 4, 4′-Bis(3-hydroxypropoxy)benzophenone, 4, 4′-Bis(6-hydroxyhexyloxy)benzophenone, 4, 4′-Bis(11-hydroxyundecyloxy)benzophenone] and two aliphatic-aromatic diols with sulfur linkages [4, 4′-Bis[(2-hydroxyethyl)thio]benzophenone, 4, 4′-Bis[(3-hydroxypropyl)thio]benzophenone] have been characterized by X-ray powder diffraction. These diols can be used for synthesis of thermoplastic nonsegmented polyurethanes. Experimental 2θ peaks positions, relative peak intensities, values of d, and Miller indices as well as unit-cell parameters are presented.

Botallackite, Cu2(OH)3Cl, from the Botallack mining area in Cornwall, United Kingdom, has been reinvestigated regarding physical, optical, chemical, and X-ray powder diffraction data. It forms emerald-green tabular crystals slightly elongated along [010] with {001} (dominant), {100}, {010}, and {011}. Botallackite is biaxial positive, 2V=70(2)°, the optical orientation is Y∧c 22(2)° (in obtuse β), Z=b. Electron-microprobe analyses gave CuO 73.26, ZnO 0.22, Cl 16.80, H2O (calc) 12.37, total 102.65, less O=Cl 3.79, total 98.86 wt %, corresponding to the empirical formula Cu1.99Zn0.01(OH)2.97Cl1.03 (based on four anions). Unit cell parameters refined from X-ray powder diffraction data are a 5.7155(5), b 6.1255(6), c 5.6336(4) Å, β 93.090(8), V 196.95(2)Å3,Z=2.

X-ray diffraction pattern from cotton fiber (dch32) grown in the Karnataka state of India has been recorded. Fiber was found to contain 17 Bragg reflections, of which 11 are broadened because of crystal size and intrinsic strain influences. Contributions to integrated intensities from intrinsic strain in the fiber have been estimated using line profile analysis. A molecular model was first constructed with standard bond lengths and angles using helical symmetry and layer-line spacings observed in the X-ray pattern. The model was then refined against observed X-ray data using the linked atom least squares (LALS) method. The refinement has been done with and without the intrinsic strain correction to find the extent of structural changes. These changes have been quantified in terms of bond angles, bond lengths, and torsion angles. Young’s modulus has been estimated for these fibers using the results of line profile analysis, and a broad agreement with the reported physical measurements has been obtained.