Sr0.5Zr2(AsO4)3 arsenate was prepared and structurally characterized by powder X-ray diffraction and by Raman and infrared spectroscopies. Its structure, which belongs to the Nasicon-type family, was refined by the Rietveld method in the R-3 space group, from X-ray powder diffraction data. The hexagonal unit-cell parameters were determined to be ah=8.965(2) Å, ch=23.955(6) Å, V=1667.43(6) Å3, and Z=6. The structure is formed by an ionic three-dimensional network of AsO4 tetrahedra and ZrO6 octahedra linked by corners with Sr2+ ions occupying half of the M1 sites in an ordered manner. Raman and infrared spectra were recorded and assignments of the stretching and bending vibrations of the AsO43− tetrahedra were made. The number of the peaks observed is in good agreement with that predicted by the factor-group analysis of the R-3 space group.

Crystal structure of 4H-SiC was refined from room-temperature X-ray powder diffraction data using the Rietveld refinement method. The refined lattice constants were determined to be a=b=3.079 93(0) Å, c=10.082 22(2) Å, and the refined overall temperature factor B=0.383(3) Å2. Using the Debye approximation, the Debye temperature was successfully determined to be 1194.8 K.

The microstructure evolution (crystallite size and microstrain) as well as the residual stress of Cu thin films of various thicknesses (250 nm, 500 nm, and 1 μm) on passivated Si substrates during isochronal annealing was investigated by in situ X-ray diffraction measurements in the temperature range between 25 °C and 250 °C. Before annealing, the thermoelastic behavior was investigated excluding the occurrence of thermally activated relaxation processes occurring above ambient temperature by in situ stress measurements below ambient temperature. On this basis, above ambient temperature, effects of stress relaxation and emerging secondary stresses (due to grain growth and annihilation of crystal defects, giving rise to a considerable tensile stress contribution development) could be identified for all three layers in the temperature regime between ambient temperature and 250 °C. Grain growth in the nanocrystalline thin films started at much lower temperatures as compared to coarse-grained materials. The results were discussed in terms of the effects of different driving forces and grain-boundary mobilities acting in nanocrystalline materials.

Quantification of potentially toxic single mineral phases in natural dusts of heterogeneous composition is critical for health hazard assessment. For example, crystalline silica, a human carcinogen, can be present as respirable particles in volcanic ash such as quartz, cristobalite, or tridymite. A method to rapidly identify the proportions of crystalline silica within mixed dust samples, such as volcanic ash, is therefore required for hazard managers to assess the potential risk of crystalline silica exposure to local populations. Here we present a rapid method for quantifying the proportions of single phases in the mineral assemblage of mixed dusts using X-ray diffraction (XRD) with a fixed curved position-sensitive detector. The method is a modified version of the whole-pattern peak-stripping (PS) method (devised by Cressey and Schofield [Powder Diffr.11, 35–39 (1996)]) using an internal attenuation standard (IAS) but, unlike the PS method, it requires no knowledge of other phases present in the sample. Ten synthetic sample mixtures were prepared from known combinations of four pure phases (cristobalite, hematite, labradorite, and obsidian), chosen to represent problematic constituents of volcanic ash, and analyzed by XRD. Results of the IAS method were directly compared with those of the PS method. The proportions of cristobalite estimated using the methods were comparable and accurate to within 3 wt %. The new IAS method involved less sample preparation and processing and, therefore, was faster than the original PS method. It therefore offers a highly accurate rapid technique for determination of the proportions of individual phases in mixed dusts.

The sin2ψ method can be formulated as a single system of simultaneous linear equations. Using this it is easy to show that the sin2ψ method is not a least-squares method. It further helps to compare the accuracies of the stress tensors obtained by the sin2ψ method and the method of least squares. Quantitative comparisons have been made for different fictitious measurements. It is shown that the unnecessary loss in accuracy by using the sin2ψ method is quite significant and by no means negligible. The same course of action has been applied to compare the so-called Dölle-Hauk method with a least-squares method; the result is similar. Some other methods for X-ray stress determination, most often similar to the sin2ψ method, and their shortcomings are also discussed briefly, together with the corresponding, more effective and more versatile least-squares method.

Hard turning, i.e., turning hardened steels, may produce the unique “hook” shaped residual stress (RS) profile characterized by surface compressive RS and subsurface maximum compressive RS. However, the formation mechanism of the unique RS profile is not yet known. In this study, a novel hybrid finite element modeling approach based on thermal-mechanical coupling and internal state variable plasticity model has been developed to predict the unique RS profile patterns by hard turning AISI 52100 steel (62 HRc). The most important controlling factor for the unique characteristics of residual stress profiles has been identified. The transition of maximum residual stress at the surface to the subsurface has been recovered by controlling the plowed depth. The predicted characteristics of residual stress profiles favorably agree with the measured ones. In addition, friction coefficient only affects the magnitude of surface residual stress but not the basic shape of residual stress profiles.

Synthetic analogs of naturally occurring nanoparticles have been studied by a range of X-ray techniques to determine their structure and chemistry, and relate these to their novel chemical properties and physical behavior. ZnS nanoparticles, formed in large concentrations naturally bymicrobial action, have an interesting core-shell structure with a highly distorted and strained outer layer. The strain propagates through the particles and produces unusual stiffness but can be relieved by changing the nature of the surface ligand binding. Weaker bound ligands allow high surface distortion, but strongly bound ligands relax this structure and reduce the overall strain. Only small amounts of ligand exchange causes transformations from the strained to the relaxed state. Most remarkably, minor point contacts between strained nanoparticles also relax the strain. Fe oxyhydroxide nanoparticles appear to go through structural transformations dependent on their size and formation conditions, and display a crystallographically oriented form of aggregation at the nanoscale that alters growth kinetics. At least one Fe oxyhydroxide mineral may only be stable on the nanoscale, and nonstoichiometry observed on the hematite surface suggests that for this phase and possibly other natural metal oxides, chemistry may be size dependent. Numerous questions exist on nanominerals formed in acid mine drainage sites and by reactions at interfaces.

The successful synthesis of ZnS hollow microspheres by a solvothermal route is reported. The synthesis was achieved by a proper selection of a sulfur source, i.e., Na2S2O3⋅5H2O or (NH2)2CS, to react with Zn(CH3COO)2⋅2H2O in mixed solvents of ethylene glycol and deionized water. The ZnS products were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), and photoluminescence spectroscopy. XRD identified the ZnS products to have either zinc blende or wurtzite structure. SEM images revealed hollow ZnS microspheres with 1 to 2 μm diameters and 100 to 200 nm shell thicknesses. TEM images confirmed that the hollow ZnS microspheres were assembled by ZnS crystalline nanocrystallites. The room-temperature photoluminescence spectrum of the zinc blende hollow microspheres showed a strong green emission at 514 nm and weak emission at 379 nm.

Preferred orientation or texture is a common feature of experimental powder patterns. The mathematics of two commonly used models for preferred orientation—the March-Dollase and the generalized spherical-harmonic models—is reviewed. Both models were applied individually to neutron powder data from uniaxially pressed molybdite (MoO3) and calcite (CaCO3) powders in Rietveld analyses, as well as the as-received powders. The structural refinement results are compared to single-crystal structures. The results indicate that reasonable refinement of crystal structures can be obtained using either the March model or generalized spherical-harmonic description. However, the generalized spherical-harmonic description provided better Rietveld fits than the March model for the molybdite and calcite. Therefore, the generalized spherical-harmonic description is recommended for correction of preferred orientation in neutron diffraction analysis for both crystal structure refinement and phase composition analysis. Subsequently, the generalized spherical-harmonic description is extended to crystal structure refinement of annealed and the aged polycrystalline Ni-rich Ni50.7Ti49.30 shape memory alloys.

Four sol-gel TiO2 powders have been prepared from titanium tetraisopropoxide. The calcined powders are then characterized by X-ray diffraction. Cell parameters are extracted using two Rietveld refinement programs (FULLPROF and MAUD) leading to close values and indicating a contraction of the a (or b) cell parameter and an expansion of the c cell parameter of the anatase phase with temperature. Crystallite size and microstrain are highly dependent not only on the sol synthesis but also on the diffraction line profile analysis (LPA) models (i.e., Williamson-Hall, Thomson-Cox-Hastings, Dehlez et al., and log-normal size distribution) employed. Discrepancies are then observed for the phase transformation critical size, the activation energy of grain growth, and the microstrain stored potential energy according to the LPA approach used to calculate the microstructural parameters.

A synthetic analogue, Ca(Ti0.6Al0.2Sb0.2)OSiO4, of antimony-bearing titanite of a composition similar to that found at St. Marcel-Praborna (Italy) was synthesized using ceramic methods and the crystal structure was refined using the Rietveld method. Unit-cell dimensions (in Å) are a=7.0184(1), b=8.7097(2), c=6.5586(1), and β=113.700(1)°. The substitution of 40% Ti by (Al+Sb) in octahedra causes a loss of long-range coherency of the off-centered Ti atoms. The space group of Sb-bearing titanite is A2/a, like other cases of M3+-M5+-doped titanites. This study confirms that titanite with up to 0.2 Sb atom per f.u. can exist and that the substitution scheme is 2Ti4+↔Al3++Sb5+.

The peak profile shape analysis has been preferentially used in the evaluation of X-ray and synchrotron powder diffraction pattern. However, neutron diffraction facilities of new generation frequently offer the instrumental resolution high enough to efficiently study the effects of broadening of neutron diffraction profiles. The present paper describes the procedure for a detailed evaluation of Bragg peak shape based on the method of transformed model fitting (TMF) which has been recently developed particularly for the treatment of neutron diffraction profiles. Microstructure modeling is performed in the reciprocal space and the convolution of the model with the instrumental resolution curve is fitted to the profiles recorded in the diffraction experiment.

Five new derivatives of N-(ω-hydroxyalkyl)-4-chlorophenoxyacetamide [namely, 2-(4-chlorophenoxy)-N-(2-hydroxyethyl) acetamide, 2-(4-chlorophenoxy)-N-(3-hydroxypropyl) acetamide, 2-(4-chlorophenoxy)-N-[1-(hydroxymethyl) propyl] acetamide, 2-(4-chlorophenoxy)-N-(2-hydroxy-1,1-dimethylethyl) acetamide, and 2-(4-chlorophenoxy)-N-{2-[(2-hydroxyethyl) amino] ethyl} acetamide] and one 2-(4-chlorophenoxy) acetohydrazide have been characterized by X-ray powder diffraction. These organic compounds are potential pesticides. New diffraction data including experimental and calculated 2θ peaks positions, values of d, experimental relative peak intensities, and Miller indices as well as unit-cell parameters are reported.

A monoclinic phase isostructural to Al4W was revealed in Al–Ni–Re close to the Al–Re terminal. It is assumed to be a ternary extension of the high-temperature Al4Re phase usually transforming in binary alloys even by sharp quenching from the existence temperatures. The powder X-ray diffraction pattern of this phase of the Al77Ni2.5Re20.5 composition was indexed for the Cm space group with a=5.1538(12) Å, b=17.410(5) Å, c=5.1546(15) Å, and β=100.548(16)°.

The biaxial stress and thermal expansion of multilayer doped-aluminosilicate environmental barrier coatings were measured in situ during cooling using microfocused high-energy X-rays in transmission. Coating stresses during cooling from 1000 °C were measured for as-sprayed and thermally cycled samples. In the as-sprayed state, tensile stresses as high as 75 MPa were measured in the doped-aluminosilicate topcoat at 375 °C, after which a drop in the stress occurred accompanied by through-thickness cracking of the two outermost layers. After thermally cycling the samples, the stress in the topcoat was reduced to approximately 50 MPa, and there was no drop in stress upon cooling. This stress reduction was attributed to a crystallographic phase transformation of the topcoat and the accompanying change in thermal expansion coefficient. The addition of a doped aluminosilicate to the mullite layer did not lower the stress in the topcoat, but may offer increased durability due to an increased compressive stress.

Tibolone is used for hormone reposition of postmenopause women and isotibolone is considered the major degradation product of tibolone. Isotibolone can also be present in tibolone API raw materials due to some inadequate synthesis. Its presence is then necessary to be identified and quantified in the quality control of both API and drug products. In this work we present the indexing of an isotibolone X-ray diffraction pattern measured with synchrotron light (λ=1.2407 Å) in the transmission mode. The characterization of the isotibolone sample by IR spectroscopy, elemental analysis, and thermal analysis are also presented. The isotibolone crystallographic data are a=6.8066 Å, b=20.7350 Å, c=6.4489 Å, β=76.428°, V=884.75 Å3, and space group P21, ρo=1.187 g cm−3, Z=2.

The modified Williamson–Hall and Warren–Averbach methods were used successfully for analyzing experimentally observed anisotropic X-ray diffraction line broadening and for determining reliable values of crystallite size and dislocation density in cerium oxide. The modified Williamson–Hall plot gives 22.3(2) nm for volume-weighted crystallite size, while the modified Warren–Averbach produces 18.0(2) nm for area-weighted grain size. The dislocation density and effective outer cut-off radius of dislocations obtained from the modified Warren–Averbach method are 1.8(3)×1015 m−2 and 15.5(1) nm, respectively.

Differences between up-cut and down-cut grinding are usually not considered since both modes are alternating during conventional face grinding. Nevertheless, there is a pronounced distinction in the fashion of material removal which could lead to unequal states of surface residual stress. By means of X-ray diffraction analysis, ground plates made from three types of steel were investigated in order to compute and compare both macroscopic and microscopic residual stress and domains of coherent scattering. With respect to the main sources of residual stress generation, i.e., plastic and thermal deformation, machining process was carried out in two types of cooling environment. The results indicate significant influence of heat removal since differences between the two grinding modes are virtually nonexistent for liquid cooling, whereas dry grinding results in higher compressive normal residual stresses for down-cut mode in comparison to the up cut.

X-ray powder diffraction data, unit cell parameters, and space group for alaptide are presented (a=21.136(4) Å, b=7.212(4) Å, c=6.126(3) Å, space group P212121, cell volume=933.8(8) Å3, and Z=4). All measured lines were indexed and are consistent with the P212121 space group. No detectable impurities were observed.

Weld residual stress (RS) measurements are often undertaken on test-pieces which have been cut out from large components, yet it remains unclear to what extent the RSs in test-pieces are representative of those present in the original component. Similarly weld mechanical performance tests are frequently undertaken on cross-weld test-pieces without a proper understanding of the level or influence of retained RS. We present a systematic study of the relaxation of longitudinal RS in thin-plate butt welds produced using different materials and welding methods (FSW, laser-MIG, and pulsed-MIG). In each case the RSs were measured repeatedly in the same location as the welds were progressively and symmetrically cut down. Although cutting inevitably leads to stress redistribution, significant relaxation of the longitudinal RS was only observed when the weld length or width was reduced to below a certain value. This critical value appears to correlate with the lateral width of the tensile zone local to the weld-line and may be considered to be the characteristic length as defined in St. Venant’s principle. Further, it was found that the level of stress relaxation as a function of weld length for all the welds studied could be collapsed onto a single empirical curve using a simple approach based on the characteristic length scales of the weld. Given the range of materials and welding methods used, this relation appears to be of general use for thin-plate welds although further work is required to test the limits of its applicability.