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Using the three slit collimation system with a divergent beam simplifies the design of a small angle X-ray scattering (SAXS) cameras and improves both flux and stability. To achieve the required low angle and a high spatial resolution, the collimation system must be optimized in the design and operation phases. Simulation of a slit divergent camera yields optimal distance between the beam defining slits and optimal distance between sample and detector at which the maximum SAXS resolution is achieved with a minimal parasitic scattering for any length of the SAXS camera. The narrower the beam defining slits and the longer the total camera length, the smaller the minimum resolvable angle and the higher the attainable resolution.

As a new method, x-ray diffraction enhanced imaging (DEI) has extremely high sensitivity for weakly absorbing low-Z samples in medical and biological fields. Conventional performance parameters, such as spatial resolution and low-contrast resolution, are not enough to describe the characteristics of a DEI system. This paper focuses on refraction-angle resolution which describes the ability of a DEI system to differentiate the x-rays refracted by the sample. The analysis of refraction-angle resolution is composed of two parts: the analysis of the single DEI image measured in a certain position of the rocking curve and the analysis of the refraction-angle image calculated by extraction methods. A 2D computer simulation experiment is performed to prove the results of the analyses. The limitations and conclusions of refraction-angle resolution are described in the end.

Electron diffraction has been recently used in the pharmaceutical industry to study the polymorphism in crystalline drug substances. While conventional X-ray diffraction patterns could not be used to determine the cell parameters of two forms of the microcrystalline GP IIb/IIIa receptor antagonist roxifiban, a combination of electron single-crystal and synchrotron powder diffraction techniques were able to clearly distinguish the two polymorphs. The unit-cell parameters of the two polymorphs were ultimately determined using new software routines designed to take advantage of each technique's unique capabilities. The combined use of transmission electron microscopy (TEM) and synchrotron patterns appears to be a good general approach for characterizing complex (low-symmetry, large-unit-cell, micron-sized) polymorphic pharmaceutical compounds.

We report the studies of structure and properties of a quasi-one-dimensional (quasi-1D) compound ${\rm BaTiS}_{3}$ BaTiS 3 under pressure. The poly-crystalline samples are synthesized by solid-state reaction method and single-crystalline samples are produced by chemical vapor transport method. The XRD measurement under ambient pressure confirms the hexagonal structure, which consists of face-sharing octahedral ${\rm TiS}_{6}$ TiS 6 chains along c-axis and displays a quasi-1D feature. When applying pressure, the synchrotron X-ray diffraction experiments show that the sample undergoes a phase transition from hexagonal phase to orthorhombic phase at around 10 GPa due to the zig–zag deformation of ${\rm TiS}_{6}$ TiS 6 chains, while the quasi-1D structure is reserved. At ambient pressure, ${\rm BaTiS}_{3}$ BaTiS 3 exhibits an insulating behavior with a band gap about 0.273 eV. When applying pressure, the sample undergoes a crossover from insulator to metal due to the enhancement of inter-chain electron hopping. [ABSTRACT FROM AUTHOR]

A series of novel [4-(2-nitrobenzyl)piperazin-1-yl](phenyl)methanone derivatives containing piperazine structures were designed and synthesized. (3,7-Dichloroquinolin-8-yl)[4-(2-nitrobenzyl)piperazin-1-yl]methanone was selected to confirm the spatial structure through X-ray diffraction. Herbicidal activity of the target compounds was evaluated against the pre-emergence of Echinochloa crusgalli L., Lolium perenne L., Amaranthus retroflexus L. and Lactuca sativa var. ramosa Hort. Herbicidal activity of compounds with different substituent on the phenyl followed an order of magnitude that was given as: donor-drawing group > neutral group > electron-drawing group on Lactuca sativa var. ramosa Hort. (2,3-Dimethylphenyl)[4-(2-nitrobenzyl)piperazin-1-yl]methanone showed stronger herbicidal activity against the pre-emergence of Echinochloa crusgalli L. and Lolium perenne, while (2-chlorophenyl)-[4-(2-nitrobenzyl)piperazin-1-yl]methanone showed stronger herbicidal activity against Amaranthus retroflexus L. and Lactuca sativa var. ramosa Hort. [ABSTRACT FROM AUTHOR]

We report the epitaxial growth of Ruddlesden–Popper nickelates, Lan+1NinO3n+1, with n up to 5 by reactive molecular beam epitaxy. X-ray diffractions indicate high crystalline quality of these films, and transport measurements show strong dependence on the n values. Angle-resolved photoemission spectroscopy reveals the electronic structure of La5Ni4O13, showing a large hole-like pocket centered around the Brillouin zone corner with a (π, π) back-folded copy. [ABSTRACT FROM AUTHOR]

Self-assemblies of the flexible ferrocenyl block (3-carboxy-1-oxopropyl)-ferrocene with Zn(II)/Cd(II) cations in the presence of different N-containing auxiliary ligands have led to four coordination complexes, namely, [{Zn(FcCOC2H4COO)2(Pbbbm)}2] · 1/2CH3OH (I), [{Zn-(FcCOC2H4COO)2(Btx)}2] · 2H2O (II), [Zn(FcCOC2H4COO)2(Bbbmd)] (III), and [Cd(η2-FcCOC2H4COO)2(Bbbmd)] (IV) (Fc = (η5-C5H4)Fe(η5-C5H4), Pbbbm = 1,4-bis(benzimidazol-1-ylmethyl)-benzene, Btx = 1,4-bis(1,2,4-triazol-1-ylmethyl)-benzene, Bbbmd = bis-(1-benzimidazolymethylene)-(2,5-thiadiazoly)-disulfide). Their structures have been determined by single-crystal X-ray diffraction analyses (CIF files CCDC nos. 948969 (I), 948970 (II), 948971 (III), 948972 (IV)), and further characterized by elemental analyses, IR spectra, and thermogravimetric analyses. Crystallographic characterization shows the two neutral complexes I and II to have dinuclear structures which are bridged through Pbbbm and btx, while complexes III and IV give mononuclear structures. The four complexes exhibit some differences in their conformations, which can be attributed to the influence of auxiliary ligands. Notably, various weak interactions are discovered in I–IV, and they have significant contributions to self-assembly, which extend the two dimers or mononuclear complexes to infinite 3D supramolecular networks. The electrochemical studies of I–IV in DMF solution display irreversible redox waves and they all show single peaks in correspondence with redox processes of Fe(II)/Fe(III) couple electron-transfer process of ferrocenyl moieties. [ABSTRACT FROM AUTHOR]

A new lanthanide coordination polymer (Ln-CP) based on Nd(III), [Nd2(Cptpy)2(Glu)2(H2O)2]n · 5n(H2O) (Ι) (HCptpy = 4′-(4-carboxyphenyl)-4,2′:6′,4″-terpyridine and H2Glu = glutaric acid), have been hydrothermally synthesized and characterized by elemental analysis, IR, single crystal X-ray diffraction (CIF file CCDC no. 1857154) and thermal analyses. Single crystal X-ray analysis (CIF file CCDC no. 1857154) reveals that compound Ι displays a (4,5)-connected 2D topological net and the Schläfli symbol of (3.43.52)(32.44.52.62), which is further extended into a 3D supramolecular network by hydrogen bonds. Additionally, the near-infrared (NIR) luminescence of Ι was investigated in the solid state at room temperature. [ABSTRACT FROM AUTHOR]

A perfect matching chart is designed to obtain the matching frequency fm and the matching thickness tm of electromagnetic (EM) attenuation material. Based on the chart, the relationship between matching parameters (fm and tm) and high-frequency dynamic parameters [μ′(f), μ″(f), and ε′(f)] are studied for Ni0.97-xZnxCo0.03Fe2O4 (NiZnCo) spinel ferrites with x=0.5 and 0.65. At tm, the spinel ferrites exhibit excellent EM attenuation characteristics with low reflectivity and broad bandwidth at very high frequency and ultrahigh frequency bands. [ABSTRACT FROM AUTHOR]

Abstract: Two new alkaline earth metal coordination polymers, which are [Ba(H2IDC)-(H3HmIDC)(H2O)2]n (I) and [Sr(H2HmIDC)]n (II) [H3IDC = 1H-imidazole-4,5-dicarboxylic acid, H4HmIDC = 2-(hydroxymethyl)-1H-imidazole-4,5-dicarboxylic acid), respectively, have been successfully synthesized under solvothermal conditions by employing H4HmIDC as the starting material. Both compounds I and II were structurally characterized by diverse techniques, such as single crystal X-ray diffraction (CIF files CCDC nos. 1839705 (I) and 1839706 (II)), FT-IR spectra, powder X-ray diffraction, and thermogravimetric analyses. Compound I exhibits a two-dimentional (2D) coordination network with a (4, 4) topology based on dinuclear [Ba2O4] as second building units (SBUs). Whereas compound II features a 3D coordination framework based on infinite 1D inorganic chains as SBUs, which can be further simplified as a 5‑connected noy topology. In addition, the photoluminescent properties of both compounds I and II were also investigated. [ABSTRACT FROM AUTHOR]

Summary: A nine‐node corotational curved quadrilateral shell element with novel treatment for rotation at intersection of folded and multishell structures is presented. The element's corotational reference frame is defined by the two bisectors of the diagonal vectors generated using the four corner nodes and their cross product. In reference frame, the element rigid‐body rotations are excluded in calculating the local nodal variables from the global nodal variables. Rotations are not represented by axial (pseudo) vectors but by components of polar (proper) vectors, of which additivity and commutativity lead to symmetry of the tangent stiffness matrix. In the global coordinate system, the two smallest components of the midsurface normal vector at each node of a smooth shell or at nodes away from the intersection of nonsmooth shells are defined as rotational variables. In addition, of the two nodal orientation vectors at intersections of folded and multishell structures, two smallest components of one vector, together with one smaller component of another vector, are employed as rotational variables, leading to the desired additive property for all nodal variables in a nonlinear incremental solution procedure. In the local coordinate system, the two smallest components of the midsurface normal vector(s) at any node of a smooth shell or in each smooth patch of nonsmooth shell are defined as rotational variables. Different from other existing corotational finite‐element formulations, the resulting element tangent stiffness matrix is symmetric owing to the commutativity of the local nodal variables in calculating the second derivative of strain energy with respect to these nodal variables. To alleviate membrane and shear locking phenomena, the membrane strains and the out‐of‐plane shear strains are replaced with assumed strains, using the Mixed Interpolation of Tensorial Components approach, for obtaining the element tangent stiffness matrices and the internal force vector. Finally, a series of benchmark, challenging smooth, folded, and multishell structures undergoing large displacements and large rotations are analyzed to demonstrate the reliability and computational accuracy of the proposed formulation. [ABSTRACT FROM AUTHOR]

Examines the composition and microstructure of the silver-bismuth-2223 oxide interface in the silver-sheathed superconducting composite. Application of Auger electron spectroscopy and x-ray diffraction analysis; Effects of the vaporization of bismuth oxide during high-temperature heat treatment in the composite; Reason for the formation of nonsuperconducting phase.

BiFeZrO ( x = 0.00-0.30) ceramics were synthesized using solid state reaction method followed by rapid liquid phase sintering, and the microstructure, electrical and magnetic properties of the synthesized ceramics were systematically investigated. The XRD patterns show that no impurity phases exist in Zr doped samples; Zr doping induces the crystal structure distortion when x ≤ 0.10, and a structural phase transition occurs when the content of Zr varies from 0.10 to 0.20. SEM observations indicate that the average grain size is remarkably decreased by Zr doping. Positron annihilation lifetime spectra results indicate that cation vacancy-type defects exist in all samples, the cation vacancy concentration increases with increasing Zr content from 0.00 to 0.20, and then decreases with further increase of Zr content. Electrical and magnetic measurements show that enhanced leakage, ferroelectric and magnetic properties are observed in Zr doped ceramics. The analysis of microstructure and properties show that the cation vacancy defect plays an important role in modulating the electrical and magnetic properties of BiFeO. [ABSTRACT FROM AUTHOR]

Powder samples of ABO3 perovskite manganites with the composition Pr0.6Sr0.4MxMn1-xO3 (M=Fe, Co, or Ni, 0.00≤x≤0.25) were synthesized using the sol-gel method. X-ray diffraction analyses showed that all three sets of samples had a single phase with an orthorhombic structure. The magnetic moment, μobs, of the samples at 10 K, decreased slowly for x≤0.10, whereas μobs decreased rapidly for x≥0.10. The dependences of μobs on the doping level x for the three series of samples were fitted successfully. In the fitting process, Mn, Fe, Co, and Ni cations were assumed to be trivalent, and the magnetic moment directions of Fe3+, Co3+, and Ni3+ cations were assumed to be canted antiferromagnetically coupled with Mn3+ cations. The cant angle φ decreased with the increase in x for x≤0.10 for Fe- and Ni-doped (x≤0.15 for Co-doped) samples and increased rapidly when x≥0.10 (x≥0.15 for Co-doped) samples. These properties are discussed using an oxygen 2p itinerant electron model, which is very similar to the oxygen 2p hole model proposed by Alexandrov et al. [ABSTRACT FROM AUTHOR]

The magnetic behaviors influenced by the hydrostatic pressure in the polycrystalline hexagonal Mn3Sn intermetallic compound are briefly reported. The crystalline structure of Mn3Sn is determined to be hexagonal with lattice parameters $a = b = 5.674$ (6) Å and $c = 4.533$ (6) Å by means of the powder X-ray diffraction and the subsequent Rietveld refinement. Two distinct transitions can be observed from the M(T) curves in the range of 150-450 K. During the cooling process, Mn3Sn sample first changes into a triangular antiferromagnetic (AFM) state with weak ferromagnetism at the Néel temperature of ~412 K, and then, it further transforms to a spiral AFM spin arrangement over a broad temperature range from 260 to 180 K at ambient pressure. With the application or the increase of hydrostatic pressures, this triangular to spiral AFM transition occurs at higher temperatures, while the magnetization of triangular AFM phase increases significantly. Such a phenomenon can be explained by the fact that the hydrostatic pressure compresses the sample and shortens the Mn–Mn separation, and thus, the moments of Mn will deviate from their ideal 120° configuration to their easy axis in the basal plane. The variations of transition temperature and maximum magnetization with applied hydrostatic pressure confirm the incremental instability of the triangular AFM arrangement under pressure. [ABSTRACT FROM AUTHOR]

In the present work, we reported an excellent magneto-caloric effect (MCE) of a binary Gd 63 Ni 37 amorphous alloy. The amorphous features of the Gd 63 Ni 37 as-spun ribbons were ascertained by their X-ray diffraction pattern, differential scanning calorimetry (DSC) curve and their magneto-caloric behaviors. The Gd 63 Ni 37 amorphous ribbon exhibits rather high magnetic entropy change peak (−Δ S m peak ), refrigeration capacity ( RC ) and adiabatic temperature rise (Δ T ad ). The binary Gd 63 Ni 37 amorphous alloy is expected to play an important role in developing high performance multi-component Gd-Ni-based amorphous magnetic refrigerants. [ABSTRACT FROM AUTHOR]

The highly efficient CuO/Co3O4 composite photocatalyst with different morphologies has been synthesized directly on Cu wire mesh by controlling the composition of cobalt-containing solid precursors via a simple hydrothermal method. The structure morphology and composition of the composite photocatalyst have been characterized by scanning electron microscopy (SEM), transmission electron microscopy (TEM), X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), and UV-visible diffuse reflectance spectra. The photocatalytic result shows that the CuO/Co3O4 coaxial heterostructure is easy to recycle and exhibit enhanced photodegradation activity for methylene blue compared to single CuO nanorod arrays under full spectrum solar light irradiation. The enhanced photocatalytic efficiency of the composite could be ascribed to the synergistic effect of CuO and Co3O4. This study provides a general and effective method in the fabrication of 1D composition NRs with sound heterojunctions that show enhancement of photocatalytic performance and facility of recycling. [ABSTRACT FROM AUTHOR]

Quantitative characterization of local strain in silicon wafers is critical in view of issues such as wafer handling during manufacturing and strain engineering. In this work, full-field X-ray microdiffraction imaging using synchrotron radiation is employed to investigate the long-range distribution of strain fields in silicon wafers induced by indents under different conditions in order to simulate wafer fabrication damage. The technique provides a detailed quantitative mapping of strain and defect characterization at the micrometer spatial resolution and holds some advantages over conventional methods. [ABSTRACT FROM AUTHOR]

A kind of core shell cathode material, (LMSAC) was prepared by coating AlF3 and carbon hybrid layer on the surface of lithium rich manganese based solid solution (LMSS) through a sol-gel process. It was characterised by X-ray diffraction (XRD) patterns, scanning electron microscope (SEM) and transmission electron microscope (TEM). Its electrochemical properties were evaluated by electrochemical impedance spectra and galvanostatic charge-discharge measurements. Owing to the AlF3/C shell, the LMSAC could deliver the initial capacities of 278, 260, 246, 230 and 210 mAh g−1 at the rates of 0·1, 0·2, 0·5, 1 and 2C in the potential range of 2-4·8 V (versus Li+/Li) respectively, exhibiting an excellent rate capability. The corresponding coulombic efficiencies are 90, 89, 87, 88 and 85% in the first cycle. After cycled at the 0·1C and 1C rates for 50 times, the LMSAC remains 97 and 96% of the initial capacities respectively, displaying an enhanced cycling performance. The results suggest that surface coating of AlF3/C hybrid layer could be a promising method to improve the electrochemical properties of the LMSS cathode materials. [ABSTRACT FROM AUTHOR]

X-ray diffraction analysis, scanning and transmission electron microscopy, thermal analysis and measurement of chemical composition were implemented to determine structure, thermal stability and chemical composition of the decagonal quasicrystal in Al73Cu11Cr16 alloy produced by long-term mechanical alloying of elemental powders followed by annealing at 700°C. According to the TEM investigation such a technique permits to produce a single-phase nanostructural quasicrystal with grain size about 60 nm. Differential thermal analysis revealed that the decagonal phase does not exist above 923°C and undergoes incongruent two-stage melting coming to the end at 1100 °C. [ABSTRACT FROM AUTHOR]

Spray forming offers attractive possibilities for the production of high speed steels technically and economically. In this paper, 10V high speed steel billets were produced through spray forming using a two-atomiser scanning facility. Its microstructure, phase composition, chemical composition and hardness were examined using a variety of techniques, including X-ray photoelectron spectroscopy, X-ray diffraction, scanning electron microscopy and transmission electron microscopy. Results showed that the as deposited 10V steel billet has a density over 99·6% of theoretical value. The microstructure is composed of the equiaxed grains with a mean size of less than 20 μm and Vanadium rich MC type carbides. The steel obtained by spray forming has a uniform carbide distribution. No measurable macrosegregation is found. This can be explained by rapid solidification of spray forming for microstructure refining. The hardness of the as deposited 10V steel reaches 42 HRC. Post-thermomechanical processing is required to further improve densities and properties. [ABSTRACT FROM AUTHOR]

The effects of hot extrusion on microstructural evolution in spray formed GH738 were investigated using X-ray diffraction, scanning electron microscopy and electron backscatter diffraction. After hot extrusion, the refined and uniform microstructures showed entirely dynamic recrystallisation (DRX) characteristics that the mean grain size was lower than 10 μm. Decreasing the extrusion temperature can achieve smaller DRX microstructures as a result of the γ′ phase, which can effectively inhibit the recrystallisation and grain growth during deformation. The carbides precipitating in the slow cooling rate after hot isostatically pressing (HIP) could be broken and distributed along the extrusion axis as a typical flow line during the extrusion. HIP can make the γ′ phase grow, while extrusion can refine it into a nearly spherical state. [ABSTRACT FROM AUTHOR]

A ferroelectric/multiferroic/ferroelectric sandwiched structure composed by NaBiTiO (NBT) and BiNdFeO (BNF) with a LaNiO buffer layer were prepared by a sol-gel method. X-ray diffraction indicated the NBT/BNF/NBT films exhibited a pure perovskite structure. The average grain size of BNF and NBT/BNF/NBT were found to be 40 and 80 nm, respectively. Interestingly, the electrical and ferroelectric properties such as leakage current, dielectric constant, and remnant polarization of NBT/BNF/NBT sandwiched layer, were superior to those of BNF single film. However, the saturation magnetization of NBT/BNF/NBT sandwiched layer was reduced. Our work suggested the NBT/BNF/NBT sandwiched layer with improved multiferroic characteristics have a promising application for future information storage devices. [ABSTRACT FROM AUTHOR]

The need of corrosion protection for metals in aggressive environments is an issue of prime importance for widespread applications. In this article, we demonstrate the properties of oxide coatings prepared in molybdate/silicate and aluminate/silicate composite electrolytes via plasma electrolytic oxidation (PEO) on Mg-Li alloy. To understand the nature of the two coatings, the surface and cross-sectional morphologies, phase composition, and chemical composition of the coatings are studied by scanning electron microscopy (SEM), electron dispersion X-ray spectroscopy (EDX), X-ray diffraction (XRD), and X-ray photoelectron spectroscopy (XPS). The corrosion resistances of oxide films are evaluated using potentiodynamic polarization and electrochemical impedance spectroscopy (EIS) in 3.5 wt% NaCl solution. In contrast to Mg-Li alloy substrate, the anti-corrosion properties of the two coated alloys are both remarkably improved. Furthermore, molybdate instead of aluminate as an additive in the electrolyte brings forth a denser and compact coating, which can provide longer corrosion protection for Mg-Li alloys. Thereby a surface protection method based on PEO in molybdate/silicate electrolyte is a promising means for producing a dark brown ceramic coating on the surface of Mg-Li alloys with the capability to corrosion protection. [ABSTRACT FROM AUTHOR]

The magnetization behaviors show a strong pinning effect on domain wall motion in optimally melt-spun Pr8Fe87B5 ribbons at room temperature. According to analysis, the coercivity is determined by the nucleation field of reversed domain, and the pinning effect, which results from the weak exchange coupling at interface, makes domain nucleation processes independent and leads to non-uniform magnetization reversals. At a temperature of 60 K, owing to the weak exchange coupling between soft-hard grains, magnetization reversal undergoes processes of spring domain nucleation in soft grains and irreversible domain nucleation in hard grains, and the pinning effect remains strong among hard grains. [ABSTRACT FROM AUTHOR]

A new 3 d-4 f coordination polymer {[SmNi(Pdc)(SO)(HO)] · HO} (HPdc = pyridine-3,5-dicarboxylic acid) has been synthesized under hydrothermal conditions and structurally determined by X-ray diffraction method. The X-ray diffraction analysis reveals the compound crystallizes in the triclinic system, space group $$P\bar 1$$, with a = 10.062(4), b = 10.249(4), c = 12.744(5) Å, α = 93.548(4)°, β = 102.601(4)°, γ = 94.022(3)°, V = 1275.4(8) Å, F(000) = 972, M = 1077.85, Z = 2, ρ = 2.624 g cm, μ = 5.55 mm, final R = 0.0299, wR = 0.0805 for 4716 independent reflections with R = 0.0204. According to the structure determination the complex is a three-dimensional (3D) network structure in which infinite lanthanide-carboxylate chains are linked by [Ni(SO)] metalloligands to form a mixed-metal coordination network. [ABSTRACT FROM AUTHOR]

Abstract: The effect of aluminum on the microstructure and properties of Cu–Ni–Si alloys has been investigated using hardness test, electrical conductivity measurement, optical microscopy, X-ray diffraction analysis, scanning electron microscopy and transmission electron microscopy. Compared with Cu–Ni–Si alloy, Cu–Ni–Si–Al alloy had finer grains. After homogenization treatment at 940°C for 4h, hot rolling by 80% at 850°C, solution treatment at 970°C for 4h, cold rolling by 50% and ageing treatment at 450°C for 60min, properties better than Cu–Ni–Si alloy have been obtained in Cu–Ni–Si–Al alloy: hardness was 343HV, electrical conductivity was 28.1% IACS, tensile strength was 1080MPa, yield strength was 985MPa, elongation percentage was 3.1% and stress relaxation rate was 9.83% (as tested at 150°C and loading for 100h). β-Ni3Si and δ-Ni2Si formed during the ageing process and the crystal orientation relationship between matrix and precipitates was : (02̄2̄)Cu(01̄1̄)β(010)δ, [100]Cu[100]β[001]δ; (111̄)Cu(111̄)β(02̄1)δ, []Cu[]β[012]δ. Addition of Al promoted the precipitation, and effectively enhanced the anti-stress relaxation property. Quasi-cleavage fracture with shallow dimples appeared in designed Cu–Ni–Si–(Al) alloy. [Copyright &y& Elsevier]

The corrosion study of the pipeline steel is extremely important for the safety of CO2 pipeline. The present work studied the effect of temperature on the corrosion behaviour of X70 steel in high pressure CO2/SO2/O2/H2O mixtures. Weight loss method was utilised to measure the corrosion rate. Environmental scanning electron microscopy and focused ion beam technology were employed to observe the morphology of product scales. X-ray diffraction was used to analyse the composition of product scales. The porosity of product scales was measured, and the exhaust gas was detected by gas chromatography. Results showed that the corrosion rate increased with the increasing temperature and then started to decline with temperature with the peak corrosion rate at 348 K. Results also showed that there was hydrogen that existed in the exhausted gas, indicating that the hydrogen evolution reaction was contained in the corrosion cathodic process. [ABSTRACT FROM AUTHOR]

A simple and hydrazine-free solution-based approach for depositing (CZTS) and (CZTSSe) absorber layers is reported. The process involves incorporating metal salts and thiourea into a single pyridine-based solution, spin-coating a precursor film, and sulfurizing with sulfur powders or selenizing using pellets in an inert atmosphere, to form the desired CZTS or CZTSSe films. X-ray diffraction and Raman spectra studies show that kesterite CZTS and CZTSSe are formed after sulfurization and selenization, respectively. The selenized CZTSSe displays higher crystallinity than the sulfurized CZTS. Photovoltaic devices (glass//CZTSSe//i-/n-/A) employing the solution precursor selenized at 500°C have yielded power conversion efficiency of 1.44% under AM 1.5 illumination. [ABSTRACT FROM AUTHOR]

Solar-blind photoresistors based on \Mg0.48\Zn0.52 \O thin films were fabricated on r-plane sapphire substrates by radio-frequency plasma-assisted molecular beam epitaxy. High-quality a-plane-orientation single-phase wurtzite \Mg0.48\Zn0.52\O thin films are demonstrated by X-ray diffraction and absorption spectra. The MgZnO photoresistors exhibit a large dark/photoresistance ratio up to \1.7 \times \10^4 with the light intensity of 0.61 \mW/cm^2 at 260 nm. The spectral response shows a sharp response peak only in the solar-blind region with maximum responsivity of \1.5 \times \10^-3\ \Omega^-1\cdot\W^-1 . [ABSTRACT FROM PUBLISHER]

Two new zinc(II) complexes, [ZnBrL] ( I) and [ZnBrL] ( II), where L is 2-[(2-isopropylaminoethylimino)methyl]-5-methoxyphenol and L is N,N-dimethyl-N′-(1-pyridin-2-yl-ethylidene)ethane-1,2-diamine, were prepared and characterized using elemental analysis, FT-IR spectroscopy, and X-ray single-crystal diffraction. In complex I, the Zn(II) atom is coordinated by one phenolic O and one imino N atoms of L and two Br atoms, forming a tetrahedral coordination geometry. In complex II, the Zn(II) atom is in a trigonal bipyramidal coordination geometry with the equatorial plane formed by the imino N atom of L and two Br atoms and with the two axial positions occupied by one pyridine N and one amino N atoms of L. In the crystal structure of I, the mononuclear zinc complex molecules are linked through intermolecular N-H...O and N-H...Br hydrogen bonds, forming chains running along the y axis. The chains are further linked via intermolecular C-H...Br hydrogen bonds. In the crystal structure of II, the mononuclear zinc complex molecules are linked through intermolecular C-H...Br hydrogen bonds, forming a 3D network. [ABSTRACT FROM AUTHOR]

The single phase Y0·2Bi1·8Mo3O12 and α-Bi2Mo3O12 catalysts have been synthesised by solid state reaction, and the Y0·2Bi1·8Mo3O12 shows better catalytic performance than α-Bi2Mo3O12 in the selective oxidation of isobutene to methacrolein. X-ray powder diffraction structural analysis, X-ray photoelectron spectroscopy and O2 temperature programmed desorption have been used to reveal the effects of doping Y on the crystal structure and catalytic activity of α-Bi2Mo3O12 induced by Y substitution for Bi. It is found that when Bi in α-Bi2Mo3O12 crystal structure is partially substituted by Y with lower electronegativity, the electronic densities of oxygen will increase, which could improve the rate determining α-H abstraction at Bi sites in the selective oxidation of isobutene to methacrolein. On the other hand, the partially regularised MoO4 tetrahedra also promote the catalytic selectivity to methacrolein due to the decrease in oxidation ability. Besides, the longer interatomic distances between Mo3 and Bi in the principal cleavage plane (010) and (010) might result in the lesser catalytic activity of Mo3 sites. [ABSTRACT FROM AUTHOR]

The single phase Y0·2Bi1·8Mo3O12 and α-Bi2Mo3O12 catalysts have been synthesised by solid state reaction, and the Y0·2Bi1·8Mo3O12 shows better catalytic performance than α-Bi2Mo3O12 in the selective oxidation of isobutene to methacrolein. X-ray powder diffraction structural analysis, X-ray photoelectron spectroscopy and O2 temperature programmed desorption have been used to reveal the effects of doping Y on the crystal structure and catalytic activity of α-Bi2Mo3O12 induced by Y substitution for Bi. It is found that when Bi in α-Bi2Mo3O12 crystal structure is partially substituted by Y with lower electronegativity, the electronic densities of oxygen will increase, which could improve the rate determining α-H abstraction at Bi sites in the selective oxidation of isobutene to methacrolein. On the other hand, the partially regularised MoO4 tetrahedra also promote the catalytic selectivity to methacrolein due to the decrease in oxidation ability. Besides, the longer interatomic distances between Mo3 and Bi in the principal cleavage plane (010) and (010) might result in the lesser catalytic activity of Mo3 sites. [ABSTRACT FROM AUTHOR]

Organic–inorganic composite photocatalyst g-C3N4–TaON with visible-light response was prepared by a milling-heat treatment method. The photocatalyst was characterized by X-ray diffraction, high-resolution transmission electron microscopy and UV-vis diffuse reflection spectroscopy. The activity of composite photocatalyst g-C3N4–TaON for photodegradation of rhodamine B is higher than that of either single-phase g-C3N4or TaON. The obviously increased performance of g-C3N4–TaON is ascribed mainly to enhancement of electron–hole separations both at the interface and in the semiconductors. [ABSTRACT FROM AUTHOR]

Nonhydrostatic compression behavior of osmium (Os) was investigated up to 58.2 GPa using radial X-ray diffraction (RXRD) together with lattice strain theory in a diamond-anvil cell. The apparent bulk modulus of Os derived from RXRD data varies from 262 GPa to 413 GPa, depending on Ψ, the orientation of the diffraction planes with respect to the loading axis. Fitting to the third-order Birch-Murnaghan equation of state, the RXRD data obtained at Ψ = 54.7° yields a bulk modulus K0 = 390 ± 6 GPa with pressure derivative K′ 0 fixed at 4. The ratio of differential stress to shear modulus t/G ranges from 0.024 to 0.029 at the pressures of 15.7–58.2 GPa. The yield strength was observed to increase with compression and reach the value of 11.7 GPa at the highest pressure. This confirms that Os is the strongest known pure metallic material compared with the reported stiff elemental metals such as W, Mo and Re. It was found that the apparent c/a ratio changed with the nonhydrostatic compression, as well as the orientation Ψ in our experiments. Moreover, the aggregate moduli of Os at high pressure were determined from the RXRD measurements. [ABSTRACT FROM AUTHOR]

The structural details of the Pr1-xSrxFeAsO (1111) superconducting system are analyzed using data obtained from synchrotron x-ray diffraction and the structural parameters are carefully studied as the system moves from non-superconducting to hole-doped superconducting with an increase of the Sr concentration. Superconductivity emerges when the Sr doping amount reaches 0.221. The linear increase of the lattice constants proves that Sr is successfully introduced into the system, and the Sr concentration can be accurately determined by electron density analyses. The evolution of structural parameters with Sr concentration in Pr1-xSrxFeAsO and comparison of them to other similar structural parameters of the related Fe-based superconductors suggest that the interlayer space between the conducting As-Fe-As layer and the insulating Pr-O-Pr layer is important for improving Tc in hole-doped (1111) superconductors, which seems to be a different trend from that encountered in the electron-doped systems. [ABSTRACT FROM AUTHOR]

Abstract: The martensitic structure in the air-cooled Cu–11.91Al–2.48Mn–0.1Zr (wt%) alloy and its variation upon heating has been studied by X-ray diffraction and TEM. The forward and reverse thermoelastic transformation behavior has been studied by voltage measurement. The shape memory ratio of the alloy aged at 150°C (in martensite state) for different times up to 100h, or heated to different temperatures up to 620°C followed by air cooling, has been measured. The air-cooled state of the alloy has a monoclinic martensitic structure M18R, which closely matches the N18R structure. This structure remains almost unchanged when the alloy is heated to 400°C. When the alloy is heated to 620°C, only a small amount of γ2 phase precipitates and a shape memory ratio of 92% is achieved. When the alloy is aged at 150°C for 100h, a shape memory ratio of 97.2% is achieved. [Copyright &y& Elsevier]

By X-ray diffraction combined with Rietveld structure refinement, the crystal structure of FeZn13 was determined experimentally in this study. The results indicated that the structure of FeZn13 is monoclinic and the lattice parameters are a = 1.3408 nm, b = 0.7605 nm, c = 0.5074 nm, and β = 127.206°. It was confirmed that Fe atoms occupy the 2c position (0, 0, 0.5) in space group C2/ m, and the coordinates of Zn atoms at the Zn(1) position are (0.114, 0.5, 0.293), which supports the results from Belin et al. ( Acta Cryst. C 56:267, 2000). In addition, an atomistic calculation was carried out to determine the crystal structure based on the interatomic potentials obtained using the lattice inversion method, and Fe atoms are substituted by Zn atoms in the narrow solubility range of FeZn13, which is the fundamental for studying the solubility and site preference of alloying elements of FeZn13. Good agreement between the experimental results and the theoretical calculations was achieved. [ABSTRACT FROM AUTHOR]

Two Al2O3–TiB2 composite coatings were deposited by axial plasma spray using two types of feedstocks. One of the feedstocks was a conventional micrometre sized Al2O3–30 wt-%TiB2 composite powder from a self-propagating high temperature synthesis (SHS) process. The second was fabricated by spray drying SHSed Al2O3–30 wt-%TiB2 composite powder doped with 10 mass-% nanosized Al2O3 powder. The microstructure of the feedstocks and as sprayed coatings were comparatively investigated by scanning electron microscope and X-ray diffraction. Wear resistance of as sprayed coatings were assessed using block on ring wear test at room temperature. Results showed that Al2O3–TiB2 composite coatings were composed of α-Al2O3, γ-Al2O3, TiB2 and a small amount of TiO2. TiB2 that mostly remained in the shape of undeformed particle were dispersedly distributed in the matrix of the composite coatings. The coating from spray dried powder exhibited finer and denser microstructure and demonstrated better wear resistance than the coating from the SHSed powder under the same sliding conditions. [ABSTRACT FROM AUTHOR]

Electrical and structural properties of metal-oxide-semiconductor capacitors having as dielectric nanoscopic LaAlO3 or HfAlOx. films deposited on nitrided or nonnitrided Si substrates were investigated. The electrical superiority of RuO2/HfAlOx/SiON/Si stacks was evidenced by a dielectric Constant of 19 and a leakage current density of 67 mA/cm2 at a gate voltage of - 1 V, for a capacitance equivalent to silicon oxide thickness of 1.1 nm. Morphology, composition, and structure of the stacks were accessed by X-ray diffraction and refiectometry, spectroscopic ellipsometry, X-ray photoelectron spectroscopy, and narrow resonant nuclear reaction profiling with isotopic substitution. In spite of presenting crystalline phases associated with HfO2, the HfAlOx. dielectric layers led to a smoother and thinner interfacial layer, improved by the thermal nitridation of the Si substrate prior to high-K deposition. This SiON-like interlayer thickness is self-limited even after postdeposition annealing owing to the formation of an effective diffusion barrier by the strong N-Si-N and N-Si-O-N bonds, which is also effective in preventing substrate oxidation. [ABSTRACT FROM AUTHOR]

A micro-porous composite polymer electrolyte (MCPE) was prepared in situ by adding TiO2 nanoparticles from the hydrolysis of titanium tetrabutoxide to a solution of poly(vinylidenefluoride-co-hexafluoropropylene) [P(VDF-HFP)] copolymer. The prepared microporous polymer films (MCPFs) were characterized by scanning electronic microscopy, X-ray diffraction, thermogravimetric analysis, FT-IR and electrochemical interface resistance. After the addition of TiO2 nanoparticles the polarity of CF2 groups in the polymer chains and the crystallinity of the MCPFs decreased. When the composite polymer film contained 8.5 wt% of TiO2 nanoparticles the MCPE exhibited excellent electrochemical properties such as high ionic conductivity, up to 2.40 × 10−3 S cm−1 at room temperature. [ABSTRACT FROM AUTHOR]

Micro-alloyed titanium aluminides and TiAl-based composite with a fully dense structure have been synthesized by a powder metallurgical method. X-ray diffraction and EDX studies show that the monolithic TiAl-based alloy and its composite consist of TiAl and Ti3Al compounds with the former as the major phase. Additions of Nb and/or (Mo + Cr) exert remarkable effects on the resultant phase compositions and mechanical properties of TiAl-based alloys. Both the added Mo and Cr elements are dissolved into the TiAl-based compounds to exhibit solid solution strengthening effect whereas Nb is only partially dissolved and the rest appears in the Nb-rich compound, Nb2Al. In general, the micro-alloyed TiAl and the composite exhibit superior flexural strength and fracture toughness to TiAl-based monolithic compound. [ABSTRACT FROM AUTHOR]

Abstract: The texture evolution of continuous cast (CC) AA 3105 aluminum alloy during cold rolling was investigated by X-ray Bragg diffraction. The influence of the precipitation state on the texture evolution during rolling was determined. The results show that the precipitates in a CC AA 3105 aluminum alloy affect the texture evolution during rolling. As the amount of precipitates increases and the size of precipitates decreases, the rate of disappearance of the cube, r-cube, and remainder components and the rate of formation of the β fiber decrease. The presence of large precipitates in a CC AA 3105 aluminum alloy hardly affects the texture evolution. [Copyright &y& Elsevier]

A cancer candidate, compound 1, is a weak base with two heterocyclic basic nitrogens and five hydrogen-bonding functional groups, and is sparingly soluble in water rendering it unsuitable for pharmaceutical development. The crystalline acid-base pairs of 1, collectively termed solid acid-base complexes, provide significant increases in the solubility and bioavailability compared to the free base, 1. Three dicarboxylic acid-base complexes, sesquisuccinate 2, dimalonate 3, and dimaleate 4, show the most favorable physicochemical profiles and are studied in greater detail. The structural analyses of the three complexes using crystal structure and solid-state NMR reveal that the proton-transfer behavior in these organic acid-base complexes vary successively correlating with ΔpKa. As a result, 2 is a neutral complex, 3 is a mixed ionic and zwitterionic complex and 4 is an ionic salt. The addition of the acidic components leads to maximized hydrogen bond interactions forming extended three-dimensional networks. Although structurally similar, the packing arrangements of the three complexes are considerably different due to the presence of multiple functional groups and the flexible backbone of 1. The findings in this study provide insight into the structural characteristics of complexes involving heterocyclic bases and carboxylic acids, and demonstrate that X-ray crystallography and 15N solid-state NMR are truly complementary in elucidating hydrogen bonding interactions and the degree of proton transfer of these complexes. [ABSTRACT FROM AUTHOR]

A new sesquiterpenoid, O-methyl nakafuran-8 lactone (1) has been isolated from a Hainan sponge Dysidea sp. and the structure of the new compound proposed by spectral data, was confirmed by X-ray diffraction analysis. The complete ¹H- and 13C-NMR assignments were made on the basis of detailed 2D NMR spectral analysis. Compound 1 showed strong inhibitory bioactivity against PTPIB with IC50 value of 1.58 µM. [ABSTRACT FROM AUTHOR]