A direct method for determining powder diffraction data from a range of depths is described, where the linear absorption coefficient may vary with depth. A series of traditional data collections with varying angles of incidence are required, and the X-ray diffraction data arising from specific depths will be calculated by the transformation of these measured, angle-dependent spectra. These may then be analysed using any conventional method in order to gain information about characteristics of the sample in question at specific depths. Regularisation techniques have been used to solve the governing Fredholm integral equation to determine the depth-dependent diffractograms. The method has been validated by the use of simulated data having known model profiles, and has also been applied to experimental data from polycrystalline thin film samples.

Two different approaches for studying sample’s contributions to diffraction-line broadening are analyzed by applying them to several nickel hydroxide samples. Both are based in the refinement of powder diffraction data but differ in the microstructural model used. The first one consists in the refinement of the powder diffraction pattern using the FAULTS program, a modification of DIFFaX, which assigns peak broadening mainly to the presence of stacking faults and treats finite size effects by convolution with a Voigt function. The second method makes use of the program FULLPROF, which allows the use of linear combinations of spherical harmonics to model peak broadening coming from anisotropic size effects. The complementary use of transmission electron microscopy has allowed us to evaluate the best approach for the Ni(OH)2 case. In addition, peak shifts, corresponding to reflections 10l (l≠0) were observed in defective nickel hydroxide samples that can be directly correlated with the degree of faulting.

The low-cycle fatigue behavior of a cobalt-based superalloy was studied in situ using neutron–diffraction experiments. The alloy exhibited stress-induced formation of a hexagonal-close-packed (hcp) phase within its parent face-centered-cubic (fcc) phase at ambient temperature under strain-controlled fatigue conditions with a total strain range, Δε=2.5%. The (101) hcp peak was first observed during the 12th fatigue cycle under the given conditions following a period during which no hcp phase was detected. Subsequently, the intensity of the hcp peaks increased as fatigue progressed. Furthermore, within a single fatigue cycle, the intensity of the (101) hcp peak decreased during the compression half-cycle and increased again when the specimen was subjected to a subsequent tensile strain. The result suggests that the fcc to hcp transformation is partially reversible within one fatigue cycle.

X-ray powder diffraction data for the high temperature phase of NaBi3V2O10 obtained from in situ high temperature XRD studies are presented. NaBi3V2O10 undergoes a phase transition from triclinic to monoclinic at about 600 °C. The unit cell parameters of the high temperature monoclinic phase at 600 °C are: a=12.3899(21), b=5.5642(10), c=7.1543(18) Å and β=98.393(16)°, V=487.94(13) Å3 and Z=2, ρcal=6.20 g∕cc. On further increasing the temperature, it partially decomposes to a γ-Bi4V2O11 type phase. The details of this phase as well as the stability of NaBi3V2O10 are discussed.

The room temperature powder pattern of abacavir hemisulfate (anti-HIV reverse transcriptase compound) was indexed using 2θ values obtained from a powder pattern spiked with an internal standard. The resulting unit cell values for the monoclinic I2 cell [nonstandard setting of C2 (No. 5)] are a=13.278(1) Å, b=8.437(1) Å, c=14.259(2) Å, β=93.87(1)°. There are two formula units [(C14H16N6O)2.H2SO4] per unit cell and Dx=1.390 g∕cm3.

A commercially available solid-state multiple strip detector was successfully used to perform reciprocal space mapping and to significantly reduce the data collection time as compared to conventional setups. The quality of the data benefits from the detector’s unique properties such as a high local linearity range and high dynamic range. This paper describes maps of symmetrical and asymmetrical reflections taken on different kinds of samples. A quasiperfect AlGaAs∕GaAs Multiquantum Well Structures (MQW) was used to evaluate details about the instrumental function. The main application of the proposed setup is for less perfect materials similar to GaN-based structures. A study of the thermal stability of a metal-organic chemical-vapor deposition grown InGaN∕GaN MQW by means of in situ temperature-dependent reciprocal space mapping demonstrates the possibilities of the new setup.

The diosgenin, (25R)-spirost-5-en-3β-ol, was isolated from rhizomes of dioscorea meridensis and characterized by X-ray powder diffraction, IR and MS. The diosgenin was found to be monoclinic, with refined unit cell parameters a=16.774(3), b=7.259(2), c=10.383(2) Å, β=92.74(2)°, V=1262.9(3) (Å3), Z=2, Dx(g∕cm−3)1.089, with space group P21 (No. 4).

Structure determination of 3,5-dimethoxybenzyl bromide and 3,4,5-trimethoxybenzyl bromide has been carried out from laboratory powder X-ray diffraction data using the direct-space Genetic Algorithm technique for structure solution followed by Rietveld refinement. These two compounds are of interest for their potential use as building blocks for the synthesis of dendritic materials. Although the two molecules differ only in the presence/absence of the methoxy group at the 4-position of the aromatic ring, the structural properties of the two materials are significantly different.

CheMin is a miniature X-ray diffraction/X-ray fluorescence instrument that is included in the payload of the Mars 2009 Mars Science Laboratory mission. A portable CheMin prototype was built to test the capability of the instrument for remote in situ mineralogical characterization of geological materials. The instrument was successfully deployed at a variety of Mars analog sites in Death Valley, CA, in May 2004.

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.

Four heterometallic carbonyl complexes: (1) Cp(CO)2MnPt(μ-C=CHPh)dppm) (2) [Cp(CO)2MnCu(μ-C=CHPh)(μ-Cl)]2, (3) CpMnFe2(μ3-C=CHPh)(CO)8, and (4) η4-[Cp(CO)2MnC(CO)CHPh]Fe(CO)3 have been studied by X-ray powder diffraction and their unit cell parameters are reported. Orthorhombic cell parameters for complex (1) are a=18.5719(14) Å, b=18.6092(14) Å, c=23.8117(18) Å, Z=8, space group Pbca. Monoclinic cell parameters found for complex (2) are a=11.5816(5) Å, b=7.9784(5) Å, c=16.7819(7) Å, β=105.460(2)°, Z=2, space group P21∕n. Orthorhombic cell parameters for complex (3) are a=13.5260(9) Å, b=15.1487(10) Å, c=10.3330(6) Å, Z=4, space group Pna21. Monoclinic cell parameters for complex (4) are a=10.3545(45) Å, b=8.0002(43) Å, c=21.8355(95) Å, β=102.89(2), Z=4, space group P21∕c. Parameters found for complexes (1–4) are in good agreement with those obtained from single crystal X-ray diffractometry.

The diffraction pattern of nanocrystalline Ce0.9Zr0.1O2 was analyzed by whole powder pattern modeling, a recently proposed method for the study of line broadening. The main result in this typical case of study—the crystalline domain size distribution—matches closely the corresponding information obtained by transmission electron microscopy. Further information on nature and content of lattice defects is also discussed.

A series of mixed fluoride compositions with PbF2 and ScF3 were prepared by heating the intimate mixtures of component fluorides at 600 °C for 10 h followed by slowly cooling to room temperature. The products obtained were analyzed by powder XRD to reveal the phases present in them and hence the low-temperature phase equilibria in the PbF2-ScF3 system. The phase equilibria show the fluorite-type solid solution up to the composition of about 15 mol% of ScF3 in the PbF2 lattice. The unit cell volume decreases with increasing ScF3 contents in the fluorite-type solid solutions. Beyond the solubility limit, the biphasic mixture of the cubic fluorite-type solid solution and leftover ScF3 is found to exist.

Structural characterization from powder diffraction of compounds not containing isolated molecules but three-dimensional infinite structure (alloys, intermetallics, framework compounds, extended solids) by direct space methods has been largely improved in the last 15 years. The success of the method depends very much on a proper modeling of the structure from building blocks. The modeling from larger building blocks improves the convergence of the global optimization algorithm by a factor of up to 10. However, care must be taken about the correctness of the building block, like its rigidity, deformation, bonding distances, and ligand identity. Dynamical occupancy correction implemented in the direct space program FOX has shown to be useful when merging excess atoms, and even larger building blocks like coordination polyhedra. It also allows joining smaller blocks into larger ones in the case when the connectivity was not a priori evident from the structural model. We will show in several examples of nonmolecular structures the effect of the modeling by correct structural units.

X-ray diffraction investigations of two phenol derivatives - 2,2′-Thiobis(4-methyl-6-tert-butylphenol) and 2,2′-Methylenebis(4-methyl-6-tert-butylphenol) were carried out. Both compounds at room temperature have similar cell volume and the same number of molecules in an unit cell. However, 2,2′-Thiobis(4-methyl-6-tert-butylphenol) crystallizes in the monoclinic system with unit cell parameters refined to a=0.8278(2) nm, b=1.2968(4) nm, c=1.9493(7) nm, β=90.93(2)°, space group P21∕n(14), whereas 2,2′-Methylenebis(4-methyl-6-tert-butylphenol) crystallizes in the orthorhombic system with unit cell parameters refined to a=1.6203(5) nm, b=1.2827(5) nm, c=1.0197(3) nm, space group Pna21(33). The investigated C22H30O2S turned out to be a new polymorph of 2,2′-Thiobis(4-methyl-6-tert-butylphenol).

Microcalorimeter X-ray detectors using a transition edge sensor depend for their linearity and energy scale on the stability of the operating point on the transition curve. We report on some sources of energy scale drift in microcalorimeter X-ray detectors and the manner in which they have been addressed. Previously observed drifts of >10 eV∕h have been reduced to 1–2 eV∕h. This improved stability has resulted in the observation of X-ray fluorescence linewidths of ⩽12 eV over 6 h of counting time.

Crystallite size determined by X-ray line profile analysis is often smaller than the grain or subgrain size obtained by transmission electron microscopy, especially when the material has been produced by plastic deformation. It is shown that besides differences in orientation between grains or subgrains, dipolar dislocation walls without differences in orientation also break down coherency of X-rays scattering. This means that the coherently scattering domain size provided by X-ray line profile analysis provides subgrain or cell size bounded by dislocation boundaries or dipolar walls.

A new micro-X-ray flourescence (XRF) instrument was developed in combination with an atomic force microscope (AFM). A small pinhole of 5 or 10 μm was made on the AFM cantilever. The center of the micro-X-ray beam generated by a polycapillary X-ray lens was passed through the pinhole. The present experiment demonstrated that the size of the original X-ray beam of 48 μm produced by the polycapillary lens was reduced to about 10 μm. This instrument enables both observation of the surface morphology by the AFM and elemental analysis by micro-XRF.

Drilling a hole in the blade of a vibrating spatula makes a simple tool for both handling and filling capillary tubes. It is especially useful for filling capillaries with air-sensitive samples in a glove box.