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A swelling pressure cell is introduced to measure apparent swelling pressure (ps) and basal spacing of montmorillonite (d001) simultaneously for compacted bentonite during water absorption. Specimens with an initial dry density of up to 1·7 Mg/m3 were prepared with initially oven-dried bentonite powder. Results show that the ps time history curve has four stages: a sharp increase to the peak swelling pressure (pp); a drop to a valley swelling pressure (pv); another increase to the initial swelling pressure for equilibrium (pei); and equilibrium swelling pressure (peq). Meanwhile, d001 changes from 0·98 nm to 1·26 nm, 1·58 nm, 1·90 nm and 4·0 nm gradually during water absorption. Results imply that crystalline swelling of montmorillonite serves an important role for interpretation of ps behaviour of tested specimens. Another testing programme to measure ps compacted bentonite only was conducted using the swelling pressure cell. Results suggest that specimen dry density closely correlates with feature points of ps time history (i.e. pp, pv, pei and peq), which is consistent with results of earlier studies. Importantly, the 2 mm specimen thickness was used, which reduced the test duration to less than 24 h. Evidence from experiments suggests that the swelling pressure cell is a powerful and inexpensive tool for studying the swelling behaviour of compacted bentonite.

SnO2 is an n-type semiconductor and a transparent conducting oxide and has apt properties in a gas sensing material, photovoltaic cells, fuel cells, batteries etc., Nanocrystalline tin oxide (SnO2) powders with different grain sizes were prepared by chemical co-precipitation method. Synthesised nanopowder XRD data were analyzed with different tools. X-ray diffraction (XRD) analysis mainly used to determine the crystal structure of nanomaterials such as ZnO, CuO, CdO and SnO2, etc., Pure SnO2 test conditions were set to be Cu-Kα XRD source, accelerating voltage 40 kV, acceleration currency 40 mA, scan range 20–80° with Ni filter (λ = 0.154056 nm). The pure SnO2 sample was exhibiting different crystalline peaks from the powder XRD study. The diffraction peak of pure tin oxide nanoparticles possesses a tetragonal rutile structure with space group P42/mnm. The FULLPROF Suite program was used for Rietveld–type analysis for pure SnO2powder diffraction data. The resultant data were compared with Nelson-Riley, Williamson-Hall plot, and Debye-Scherer methods. The lattice parameters and particle size of pure SnO2were agreed with the ICDD.No.01-077-0447data. The main advantages of these methods are low angle regions and a small number of peaks needed.

The influence of a microwave hybrid heat treatment (MHH) on the surface and in-depth mineralogical transformation of pre-sintered 3Y-PSZ was investigated. 3Y-PSZ samples were prepared by slip casting and sintered by conventional firing (1270 °C). Then, different MHH treatments from 5 to 15 min. at 1200 °C were applied to obtain a fully stabilized 3Y-TZP. The monoclinic fraction depth profiles in the first micrometres (up to 5) of thickness were investigated by means of the grazing incident X-ray diffraction technique (GIXRD). A good sintering degree with practically nil closed porosity and grain growth was achieved after MHH of 15 min. MHH increases the tetragonal phase content both in the surface and in-depth, reducing completely the monoclinic phase shell typically found after conventional sintering. A new parabolic model is proposed for the convoluted monoclinic fraction depth profile, which through the value of its horizontal asymptote allows the determination of the monoclinic shell thickness.

Cerium oxide nanoparticles were prepared by green synthesis method using Melia dubia leaves extract. The synthesized cerium oxide nanoparticles were characterized by powder X ray diffraction, Raman Spectroscopy and UV–visible spectroscopy to investigate the structural and optical properties respectively. The obtained powder X- ray diffraction data and Raman Spectrum confirmed that the prepared samples are nanocrystalline in nature and belong to cubic crystal structure. Optical absorbance was studied from the diffuse reflectance spectra and it showed that the nanoparticles are opaque in the ultraviolet light region. The dielectric characteristics of the nanoparticles were recorded, where the dielectric constant and dielectric loss factor were observed to increase with increase in frequency and temperature. The AC conductivity of the prepared sample was analyzed as a function of frequency at different temperatures and the activation energy for conduction was determined.

Structural elucidation of small molecules only available in low quantity (nanogram) is one of the big advantages of the crystalline sponge method. The optimization of various soaking parameters is crucial for effective analyte absorption and repetitive positioning in the pores of the crystal. Time-consuming X-ray diffraction measurements are necessary for data collection and confirmation of successful guest inclusion. In this work, we report a screening method to select optimal soaking conditions without the need of single-crystal X-ray diffraction analysis for individual compounds and mixtures. 14 substances were chosen as test compounds. Parallel guest soaking of individual compounds and mixtures was conducted using various soaking conditions. After evaporation of solvent, excessive material was removed, and guest molecules released through dissolution of the framework. Liquid chromatography-tandem mass spectrometry allowed the estimation of analyte trapped in the pores and the selection of optimal soaking condition dependent on the highest amount of analyte to crystal size (affinity factor). The tool allowed subsequent crystallographic analysis of ten compounds with minimal experiment time. Additionally, a study to examine the lower limit of detection of the crystalline sponge method was conducted. Determination of two target analytes was possible using only 5 ng of sample. Our study shows the potential of an affinity screening to prioritize soaking parameters by estimation of the guest concentration in a single crystal for one or multiple target compounds within a short period of time.

International audience; A binuclear cobalt(II) benzoate complex with pyridine as auxiliary ligands has been synthesized and identified by UV–Vis, IR spectroscopy, and TG-DTA analysis. The molecular structure of the complex was determined by single-crystal X-ray diffraction (SCXRD). Thermogravimetric analysis shows two steps decomposition of the present complex. The Co (II) ions are in a distorted octahedral environment [CoN2O4]. The crystal structure was stabilized by different intramolecular/ intermolecular interactions, including Van der Waals, hydrogen bonding, donor-acceptor, and π-π interactions between the pyridine rings. Furthermore, all density functional theory (DFT) calculations have been performed in the gas phase using the GGA-BLYP functional and the TZP basis set, and for the Time-Dependent Density Functional Theory (TD-DFT) calculations, several functionals have been used, namely the GGA BLYP and PBE, the hybrids B3LYP and PBE0, the SAOP potential model, and finally the range-separated CAMY-B3LYP functional with the TZP basis set. Good consistency was observed between the calculated and the experimental results. The bond dissociation energies (BDE) were calculated using the fragment analysis. The intermolecular interactions were investigated through the Molecular Electrostatic Potential (MEP) and supported by Hirshfeld charges analysis. To characterize the non-covalent interactions in the complex, (NCI plot) index has been computed and supported by AIM analysis. Also, the global and local reactivity descriptors have been calculated to highlight the reactive sites in the molecular structure. Moreover, the antimicrobial activity was evaluated by agar disk diffusion assay against seven pathogenic strains, and the antioxidant activity was estimated using four different techniques. In addition, the in vitro anti-inflammatory activity was assessed by the albumin denaturation method.

Two novel platinum(II) complexes (1 and 2) were synthesized by the reaction of the appropriate 3,5-dimethyl-4-nitroisoxazole with K2PtCl4 and characterized by elemental analysis, ESI MS spectrometry, 1H NMR and far-IR spectroscopy. The structure of trans complex 2 was additionally confirmed by X-ray diffraction. The cytotoxicity of the investigated compounds was examined in vitro on three human cancer cell lines (MCF-7 breast, ES-2 ovarian and A-549 lung adenocarcinomas) in both normoxia and hypoxia conditions. LogPs of complexes were measured using the shake-flask method. The trans complex 2 showed much better cytotoxic activity than cisplatin for all the tested cancer cell lines. Cis complex 1 was inferior to its trans isomer against all the cancer lines tested in normoxia conditions but proved superior to the reference cisplatin against the MCF-7 and A549 lines, and showed similar activity to cisplatin against the ES-2 line. To gain additional information that may facilitate the explanation of the pharmacological activity of the tested compounds, cellular platinum uptake and stability in L-glutathione solution were determined for both compounds 1 and 2.

An aryl-extended calix[4]pyrrole with four meso‑p-hydroxyphenyl substituents was investigated as a host for chloride, acetate, and benzoate anions. Crystal structures of pyridinium and imidazolium chloride complexes were obtained in which chloride ions are hydrogen bonded exo-cavity to the upper rim hydroxyl groups, and the aromatic cations are bound to the shallow cavity of the host. Furthermore, the calix[4]pyrrole formed a hydrogen bonded dimeric capsule templated by inclusion of adiponitrile guest in the endo-cavity binding site. NMR titrations revealed the preference of the OH groups of the host to bind anionic guests in solution. Benzoate anion had the highest binding constant (4 700 M−1) in acetonitrile. Density functional theory (DFT) calculations indicated that the exo-cavity complex with chloride anions was favoured by 23.2 kJ/mol over the endo-cavity complex, whereas the energies of endo- and exo-cavity benzoate complexes were of similar magnitude due to dispersion interactions between the host and the guest. peerReviewed

Staphylococcus aureus is a common opportunistic pathogen of humans and livestock that causes a wide variety of infections. The success of S. aureus as a pathogen depends on the production of an array of virulence factors including cysteine proteases (staphopains)—major secreted proteases of certain strains of the bacterium. Here, we report the three-dimensional structure of staphopain C (ScpA2) of S. aureus, which shows the typical papain-like fold and uncovers a detailed molecular description of the active site. Because the protein is involved in the pathogenesis of a chicken disease, our work provides the foundation for inhibitor design and potential antimicrobial strategies against this pathogen.

A series of wholly aromatic copolyesters P-IPAx with low melting point (Tm) derived from hydroxybenzoic acid (HBA), 6-hydroxy-2-naphthoic acid (HNA), 4,4'-dihydroxy-biphenyl (BP), terephthalic acid...

A comparison of the analysis of respirable crystalline silica direct-on-filter methods using X-ray diffraction (XRD) and Fourier transform infrared (FT-IR) spectroscopy was undertaken using 253 real workplace air samples from road construction and tunnelling, coal mining, and kitchen benchtop manufacturing in Australia. Using pure α-quartz standards, XRD and FT-IR direct-on-filter analyses produced identical test results, however, the real workplace samples showed a clear discrepancy between FT-IR and XRD results with on average a 9% positive bias of the FT-IR results. The cause of the positive bias was due to matrix interferences which was confirmed by using synthetic mixture air samples. Approximately a third of the data by direct-on-filter method using FT-IR was assessed to be invalid based on the peak height ratio criterion due to excessive interferences and weight overload limitations. The XRD method showed better results due to less interference from the common matrices. XRD could handle up to twice the sample loading and at higher loadings up to 7 mg when a correction was applied. It was also able to achieve a lower limit of detection of 2 µg filter−1 when a slower scan condition was utilized.

In this study, different types of polymers in postconsumer plastics with pure plastics have been studied. Highdensity polyethylene (HDPE1 and HDPE2), polyvinyl chloride (PVC3 and PVC4), polyethylene terephthalate (PET5 and PET6), and polypropylenes (PP7 and PP8) were compared using X-ray diffraction (XRD) and X-ray fluorescence (XRF) techniques. XRF has shown the spectral in K-lines of polymer materials present in plastics waste. The peak intensity and degree of crystallinity of commercial polymers are varied using XRD analysis. The intensity not attributable to the crystalline peaks may be regarded as the amorphous scattering and used as a template in analyzing the diffraction pattern of the samples. The XRD analysis helps to provide characteristic spectral lines whose intensities vary with the type of each constituent polymer. The combined usage of XRD and XRF techniques yielded very useful and effective results for a commercial plastic management.

X-ray and neutron powder diffraction have been used to study the crystal chemistry of Fe doped mayenite (Ca12Al14-xFexO33). Solid- state synthesis was used to prepare Ca12Al14-xFexO33 where x = 0, 0.1, 0.2, 0.5 and 0.6 and the citrate gel route was used to prepare Ca12Al14-xFexO33 where x = 0, 0.05, 0.1, 0.2, 0.3 and 0.4. X-ray powder diffraction data indicate that samples with the same composition but synthesized by the citrate gel route were more likely to be phase pure than samples obtained by traditional solid-state synthesis. The refined lattice parameters were observed to increase with increasing Fe concentration, irrespective of the synthesis method. Refined neutron powder data confirm that Fe is going into Al site rather than Ca site. A 2-point probe was used to measure the electrical properties of the Fe doped citrate gel synthesized samples and showed that the resistivity increases for the Fe doped samples compared to the undoped mayenite.

Fe2W-type ferrite BaFe2+2Fe3+16-xO27± (x =−0.8, −0.4, 0.0, 0.4, 0.8, 1.2) fine powders and magnets were synthesized by a facile ceramic route. The lattice and microstructure of the fine powders were studied by x-ray diffraction (XRD). The results show that a single magnetoplumbite structure is obtained under the condition of Fe change (x =−0.8, −0.4, 0.0, 0.4, 0.8, 1.2). The morphology of the sintered magnet was studied by scanning electron microscopy (SEM). The influence of iron content on the magnetic characteristics of BaFe2+2Fe3+16-xO27± was systematically studied by controlling the pre-sintering temperature of 1300°C. The change in the remanence (Br) of BaFe22+Fe16-x3+O27± magnets with different iron content first increased and then decreased, which confirmed that the change trend of the Br was consistent with the variation in the saturation magnetization (Ms). Meanwhile, the coercivity (Hcj) and (Hcb) of the magnets was consistent with the change characteristics of the coercive force (Hc) of magnetic powder. At iron change (x) = −0.4, Ms, Br, Hc, Hcj, Hcb, and maximum energy product ((BH)max) reach maximum.

Alloys from the region of existence of the solid solution TbCo4.5SixLi0.5-x were synthesized by arc melting. Quantitative and qualitative composition of alloys and powders of electrode materials was determined by scanning electron microscopy and energy-dispersive X-ray spectroscopy. The Tb/Co/Si ratio in the samples was confirmed by X-ray fluorescence spectroscopy. The change in cell parameters within the solid solution existence was established by the results of X-ray powder diffraction (TbCo4.5SixLi0.5-x, x = 0.1–0.4: a = 4.9518(5) – 4.9324(3), c = 3.9727(4) – 3.9746(3) Å). The crystal structure of the solid solution was determined by the Rietveld method (CaCu5 structure type, space group P6/mmm). Cobalt atoms are partially replaced by silicon and lithium only in 2c position. The ability of alloys to reversibly absorb hydrogen was studied by the method of electrochemical hydrogenation. Under experimental conditions the amount of deintercalated hydrogen was about 0.19 H/f.u. The change in cell parameters after hydrogenation (volume increases from 83.74(1) to 85.54(6) Å3) and the stability of the electrode in the electrolyte solution was further confirmed by X-ray phase analysis. Measurements of the electrical resistivity of the samples indicated a decrease of resistivity value with a slight increase in the amount of alkali metal in samples.

The shock stages of 14 L6 ordinary chondrites are estimated using the random X-ray diffraction patterns of polished thin section samples and the in-plane rotation method. The mean lattice strains and grain size factors for olivine and orthopyroxene are determined from the analyses based on the Williamson–Hall plots, which depict the tangent Bragg angle and integral breadth β. The lattice strain in olivine, eOl, is distributed from ~0.05% to ~0.25%, while that in orthopyroxene, eOpx, is distributed from ~0.1 to ~0.4%, where we selected the isolated peaks of olivine and orthopyroxene. The olivine peaks have Miller indices of (130), (211), (222), and (322), while the orthopyroxene peaks have Miller indices of (610), (511), (421), (631), and (12.1.2). The intercept for integral breadth β0O1 and β0Opx for the Williamson–Hall plots correlates with the grain size of the constituent minerals. The grain size is proportional to the inverse of β0 since the β intercept increases with the shock stage. Introducing a new parameter, –ε/log β0 for olivine (0.04–0.16) and orthopyroxene (0.07–0.32) reveals a clear relationship between them: –εOpx/log β0Opx = –0.01+ 2.0 (–εOl/log β0O1) (R > 0.9). In addition, the isolated peak of plagioclase (201) systematically changes as the shock stage increases, suggesting the progress of amorphization (maskelynitization). Another parameter, (I/FWHM)Pl(201) reveals additional relationships: –εOl/log β0O1 = 0.14(±0.01) − 5.2 × 10−5 (±5.7 × 10−6) × (I/FWHM)Pl(201), and –εOpx/log β0Opx = 0.25(±0.04) − 8.9 × 10−5 (±2.6 × 10−5) × 10–5 × (I/FWHM)Pl(201). These three parameters systematically change with the shock stage, suggesting that they are suitable shock barometers. The present method is useful to evaluate the shock stage of L6 chondrites and potentially enables quantitative shock stage classification for stony meteorites.

Similarities and differences of halogen and hydrogen bonding were explored via UV–Vis and 1H NMR measurements, X-ray crystallography and computational analysis of the associations of CHX3 (X=I, Br, Cl) with aromatic (tetramethyl-p-phenylenediamine) and aliphatic (4-diazabicyclo[2,2,2]octane) amines. When the polarization of haloforms was taken into account, the strengths of these complexes followed the same correlation with the electrostatic potentials on the surfaces of the interacting atoms. However, their spectral properties were quite distinct. While the halogen-bonded complexes showed new intense absorption bands in the UV–Vis spectra, the absorptions of their hydrogen-bonded analogues were close to the superposition of the absorption of reactants. Additionally, halogen bonding led to a shift in the NMR signal of haloform protons to lower ppm values compared with the individual haloforms, whereas hydrogen bonding of CHX3 with aliphatic amines resulted in a shift in the opposite direction. The effects of hydrogen bonding with aromatic amines on the NMR spectra of haloforms were ambivalent. Titration of all CHX3 with these nucleophiles produced consistent shifts in their protons’ signals to lower ppm values, whereas calculations of these pairs produced multiple hydrogen-bonded minima with similar structures and energies, but opposite directions of the NMR signals’ shifts. Experimental and computational data were used for the evaluation of formation constants of some halogen- and hydrogen-bonded complexes between haloforms and amines co-existing in solutions.

Spanish Colonial Period brick samples dating to the 19th century from the Municipalities of Liliw and Pagsanjan in Laguna, Philippines was investigated. These samples were obtained from two church structures, a church bell tower from Liliw and a church convent from Pagsanjan. Combined X-ray diffraction (XRD), energy dispersive X-ray fluorescence (EDXRF) and Fourier transform infrared (FTIR) spectroscopy allowed the determination of chemical elements and minerals attributed to clay and sand, such as montmorillonite, quartz, corundum, hematite and calcite. On the basis of these compositions, the possible kilning conditions employed to fire the bricks during manufacture was also proposed. MATLAB™ programme was utilised in this study to interpret the data from XRD and FTIR to rationalise the overlapping peaks in the spectrum. Results show that both brick samples were made of clay material that is non-calcareous with low refractory. The firing was performed in an oxidising atmosphere or an open-air environment at an estimated temperature of between 650°C and 850°C. This preliminary study provides a baseline chemical characterisation data of colonial period bricks in the Philippines which will be useful for future conservation and restoration work not only locally but also within the Southeast Asian region.

The microstructures of Ti-6Al-4V following laser processing depend primarily on the phase transformation of β to α, but their development is constrained by the rapidly changing temperature in the small fusion zone. In-situ synchrotron X-ray diffraction was utilized to probe the rapid phase evolution in single melt tracks with high angular and temporal resolution. Both fully martensitic and mixed α+α′+β microstructures were confirmed by microscopy. Cooling rates were inferred from the lattice parameter history and complementary thermal simulation. It was found that the threshold cooling rate for fully martensitic transformation is in the range between 2900 and 6500°C/s. High-speed synchrotron X-ray diffraction during operando laser processing suggests a new threshold between martensitic and diffusional phase transformation in Ti-6Al-4V occurring at higher cooling rates than previously reported.

We investigate the structural properties of Fe1−xNix/Cu/Fe1−xNix ( x=0.5, non-Invar and x=0.36, Invar) trilayers deposited on Si(100) at room temperature using the dc magnetron sputtering technique...

Positron annihilation lifetime spectroscopy was used to examine grown-in defects in Cd1–x Zn x Te mixed crystals as a function of Zn content (x = 0, 0.07, 0.11, 0.49, 0.9, 0.95, 1) and measuring temperature. All samples were prepared using the high-pressure modified vertical Bridgman–Stockbarger method. The crystal structure and material phase were characterized by X-ray diffraction. The positron lifetime spectra reveal the presence of both open volumes and shallow traps regardless of the sample composition. In particular, both average and bulk lifetimes are found to be much higher in ternary alloys (CdZnTe) than those in binary systems (CdTe and ZnTe). This originates from distinct differences in average electron densities and the nature of open-volume defects between binary and ternary samples. Competition in positron trapping with increasing Zn content is observed between defects characteristic for both structural systems. Moreover, a clear correlation is shown between defects and the lattice thermal conductivity of studied samples. The applicability of the positron trapping model to CdTe-based materials is discussed.

The structure and effects of thermally stabilized PAN original fibers were characterized utilizing a mixture of volume density, color change observations, flame tests, X-ray diffraction (XRD), infrared spectroscopy (FT-IR), and thermogravimetric analysis (TGA) measurements. The results obtained from the analysis of XRD work showed the conversion of the original molecular structure from a highly laterally ordered condition to a disordered amorphous structure. The experimental results acquired from FT-IR analysis indicated rapid and concurrent aromatization and dehydrogenation reactions assisted by the formation of oxygen-containing functional groups. TGA analysis showed a carbon yield of 72% at 1000 °C. The application and use of NH4Br pretreatment are expected to increase the productivity of carbon fiber processing at lowered cost by significantly reducing the processing time necessary for the successful completion of thermal stabilization reactions.

A 30 year-old PuF4 sample consisting of brown powder (PuF4-b) and pink granules (PuF4-p) was analyzed. X-ray diffraction shows the bulk is comprised of three compounds: PuF4, PuO2, and PuF4·1.6H2O. Broadening of PuF4 XRD peaks suggests possible $$\upalpha$$ -damage. After annealing at 650 °C, crystalline PuF4 and PuO2 remain. Thermogravimetric analysis and differential scanning calorimetry—with simultaneous evolved gas analysis—of the separated PuF4-p and PuF4-b components reveal a distinct sequence of reactions. Dehydration occurs between ~ 90 and 300 °C. Exothermic annealing of the $$\upalpha$$ -damage occurs in two stages: at 350–355 °C and at 555–558 °C. Hydrofluoric acid, fluorine and helium desorb during the first exotherm. Above 700 °C, PuF4 reacts with PuO2, resulting in oxygen release and mass loss.

In the present study, hexagonal structured borate phosphors BaLaB9 O16 were prepared using a combustion method with colour-tunable emission properties achieved by varying the doping concentration of Eu3+ and Tb3+ in the cluster. The as-prepared materials were analyzed for structural and morphological parameters through X-ray diffraction (XRD) and field emission scanning electron microscopy (FE-SEM) studies. Tuning of colour was predicted through the photoluminescence and photoluminescence excitation spectra of the materials that showed good green and red emissions when doped with Tb3+ and Eu3+ , respectively, whereas the emission of the co-doped sample (Eu3+ and Tb3+ ) can be varied from the green region to red region by varying the excitation range from 207 to 254 nm.

A compound layer is formed by ingress of nitrogen from an external nitrogen source into the surface layer and the formation of nitrides when the solubility of nitrogen in the bulk material is exceeded. In the surface layer, where the nitrogen concentration is at its maximum level, the nitrides form a closed layer. The compound layer continues to contain alloy nitrides which have formed from the carbides and other precipitates from the bulk material. The properties of the compound layer have a decisive influence on the wear and fatigue behavior of the loaded surfaces. The current investigations deal with the extensive characterization of compound layers that have been produced in heat treatment processes with the aim of producing stress-resistant nitriding layers. The commonly used nitriding and quench and temper (Q&T) steels 31CrMoV9 and 42CrMo4 served as examination material. The structure of the compound layers was varied within the nitriding trials regarding the phase composition, porosity and layer thicknesses. The phase composition of the compound layers was determined by special etching, scanning electron microscopy (SEM), X-ray diffraction and GDOES.

Waste recycling is beneficial not only for the environment but also for the economy and the society at large. Corn stalks, the most abundant crop waste, are processed with oven drying, steaming, complex enzymatic hydrolysis (cellulase, xylanase, β-glucanase and pectinase), and fermentation (by Candida utilis and Pachysolen tannophilus), were analyzed via X-ray diffraction, Scanning Electron Microscopy (SEM) and Infrared Spectroscopy (IR). The results indicated that thermophilic digestion destroyed glycosidic bonds and fibrous crystal have a significant effect on the degradation of the corn stalks, while complex enzyme hydrolysis only slightly degraded fibrous crystal. Fermentation did not significantly reduce fibrous crystal. Therefore, our research suggested that thermophilic digestion is the appropriate way to increase the saccharification rate and feed yield of corn stalks.

X-ray diffraction (XRD) is often utilized as a method of determining bulk sample crystallite size in powder characterization. While it is generally accepted that XRD peak broadening allows for qualitative crystallite size comparisons, its use for quantitative information is still debated. This study investigates the quantitative capability of XRD for determining the crystallite sizes of magnesium oxide nanocrystals by examining the precision, accuracy and uncertainty using the whole pattern (WP) weighted least-squares and Williamson–Hall (WH) methods. The precision of the methods was investigated by re-preparing, re-running and re-analysing identical samples. Both methods were found to be precise within 2 nm. The accuracy of the methods was investigated by comparing them against independent crystallite size analyses using visual particle identification from scanning electron microscopy micrographs and from indirect calculations using Brunauer–Emmett–Teller (BET) adsorption-determined surface areas. The WP method was found to be more accurate than the WH method, which consistently underpredicted the crystallite size. Finally, the confidence of the methods was investigated using a Bayesian inference statistical inversion method. The WP method was found to have a narrower confidence distribution in its crystallite size determination than the WH method. The broad WH confidence indicates that reliable quantitative single-measurement crystallite size determinations are not feasible using the WH technique. However, the WP method demonstrated precision, accuracy and confidence, allowing quantitative crystallite size determinations to be made.

In this paper, nanocrystalline Mg-ferrites have been synthesized by the low-cost sol-gel auto-combustion method using iron and magnesium nitrates as starting materials. The as-prepared sample was annealed at temperatures of 200°C, 400°C, 600°C, 800°C, and 1000°C in an air atmosphere to investigate the effect of annealing temperature on the physical properties. The structural and magnetic properties of the annealed ferrites were studied using x-ray diffraction, Fourier transform infrared (FTIR) and Raman spectroscopy, and vibrating-sample magnetometer. The crystalline size of the nano-crystallites increased from 12 nm to 51 nm with an increase in annealing temperature from 200°C to 1000°C. Raman spectroscopy measurements revealed the presence of a spinel structure where A1g and Eg modes occur along different bond lengths of Fe/Mg-O, due to different ionic radii of Mg+2 and Fe+3 ions. The two prominent vibration frequency peaks along different bond lengths for the cubic spinel materials were confirmed using the FTIR spectra. The saturation magnetization was found to increase from 0.71 μB/f.u. to 1.16 μB/f.u. with increasing annealing temperature from 200°C to 1000°C. The magnetization results show that the magnetic properties of the nanocrystalline Mg-ferrites improved with annealing temperature.

The data on the ion-plasma sputtering of composite targets of the systems (Fe, Co, Ni) – (Ag, Bi) whose components do not mix in the liquid state is presented. The lattice parameters and sizes of c...

Characterization of the thermal expansion in the rare earth di-titanates is important for their use in high-temperature structural and dielectric applications. Powder samples of the rare earth di-titanatesR2Ti2O7(orR2O3·2TiO2), whereR= La, Pr, Nd, Sm, Gd, Dy, Er, Yb, Y, which crystallize in either the monoclinic or cubic phases, were synthesized for the first time by the solution-based steric entrapment method. The three-dimensional thermal expansions of these polycrystalline powder samples were measured byin situsynchrotron powder diffraction from 25°C to 1600°C in air, nearly 600°C higher than otherin situthermal expansion studies. The high temperatures in synchrotron experiments were achieved with a quadrupole lamp furnace. Neutron powder diffraction measured the monoclinic phases from 25°C to 1150°C. The La2Ti2O7member of the rare earth di-titanates undergoes a monoclinic to orthorhombic displacive transition on heating, as shown by synchrotron diffraction in air at 885°C (864°C–904°C) and neutron diffraction at 874°C (841°C–894°C).

Chemical vapor deposition (CVD), a low-cost and a scalable deposition technique, allows the growth of methylammonium lead iodide (MAPbI3) films without the use of solvents, substantially increasing air stability while also inducing the stable cubic phase at room temperature and at pressures as low as 0.25 GPa. MAPbI3 thin films were grown by a facile two-step low-pressure vapor deposition process in a single reactor. This method results in films, which are usually in the tetragonal phase (space group: I4/mcm) and occasionally in the cubic phase under ambient conditions. High-pressure synchrotron-based X-ray diffraction studies from CVD-grown MAPbI3 crystallites show that the sample remains in the cubic phase (space group: Im $$\bar{3}$$ ) between 0.25 and 3.0 GPa. Temperature-dependent transport measurements show sharp anomalies, correlating with the structural changes. The transport measurements from the CVD-grown cubic MAPI3 film is further compared with a film in the tetragonal phase.

l-methionine, boric acid and potassium carbonate were used to prepare l-methionine inserted potassium pentaborate (LMKB5) solution using deionized water as a solvent. A semi-organic crystal was grown by solvent vaporization at lab temperature. Structural analysis was performed on the LMKB5 crystal to affirm cell dimensions. Morphology of the grown crystal was confirmed by scanning electron microscopy (SEM). Energy dispersive x-ray (EDAX) study was used to obtain the elemental composition. The vibrational analysis was performed on the as-grown crystal, which confirms the presence of LMKB5. The optical analysis was performed using a UV–VIS–NIR spectrophotometer to calculate the energy gap of the title material. Thermogravimetry (TG) and differential scanning calorimetry (DSC) analysis are performed on a grown crystal to evaluate the thermal stability of LMKB5 crystal. Differential thermal analysis (DTA) curve affirms that the title material has crystalline nature due to a sharp endothermic peak at 193.49°C. Mechanical strength of the material was estimated using Vicker's microhardness. Laser damage threshold (LDT) studies were carried out to analyze surface damage tolerance stability in crystal. Grown material is essential for a second harmonic generation (SHG).

The Al0.30Ga0.70As /InGaAs/AlGaInAs/ Al0.30Ga0.70As structures with embedded InAs quantum dots (QDs) covered by strain reduced AlGaInAs capping layers have been investigated in an as-grown state using the photoluminescence (PL) and high resolution X ray diffraction (HR-XRD) methods. Two types of QD structures with different quantum well (QW) capping layers: Al0.10In0.15Ga0.75As (#1) and Al0.40In0.15Ga0.45As (#2), and buffer QW layers: In0.15Ga0.85As (#1) and In0.25Ga0.75As (#2) are compared. It is revealed that QD emission in the structure with Al0.10In0.15Ga0.75As capping (#1) is characterized by the higher PL intensity of the ground state (GS) band and smaller the full with at half maximum (FWHM), compared to those in #2. The variation of the GS emission intensity versus temperature has been monitored within the range of 10-500K. It was revealed more significant PL thermal quenching in #1 compared with #2. HR-XRD study has shown that the both QD structures are characterized by the best quality of the QW interfaces with the high numbers of Pendellösung peaks. The analysis of HR-XRD scans permits to estimate the values of the elastic strains in the studied QD structures, which were higher in #2 compared with #1. The peculiarities of PL spectra and HR-XRD are analyzed and the advances of studied QD structures have been compared and discussed.

The process dynamics for the vacuum deposition of methylammonium lead iodide (MAPbI3) perovskite was analyzed by in situ X-ray diffraction using synchrotron radiation. MAPbI3 was fabricated by alternatingly supplying PbI2 and methylammonium iodide via a laser deposition system installed at the synchrotron beamline BL46XU at SPring-8, and in situ crystallization analysis was conducted. Microscopic insights into the crystallization were obtained, including observation of Laue oscillation during the PbI2 growth and octahedral unit (PbI6) rotation during the transformation into perovskite. On the basis of this analysis, conditions that favor the construction of atomically flat MAPbI3 perovskite films were deduced.

A series of single-phase rare earth-doped bismuth ferrites were prepared by the solid state reaction method. After characterizing the samples with XRD, the bulk density measurements were carried ou...