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The mechanisms contributing to the electromechanical response of piezoelectric ceramics in the shear mode have been investigated using high-energy synchrotron x-ray diffraction. Soft lead zirconate titanate ceramic specimens were subjected to an electric field in the range 0.2–3.0 MV m−1, perpendicular to that of the initial poling direction, while XRD patterns were recorded in transmission. At low electric field levels, the axial strains remained close to zero, but a significant shear strain occurred due to the reversible shear-mode piezoelectric coefficient. Both the axial and shear strains increased substantially at higher field levels due to irreversible ferroelectric domain switching. Eventually, the shear strain decreased again as the average remanent polarization became oriented toward the electric field direction. The lattice strain and domain orientation distributions follow the form of the total strain tensor, enabling the domain switching processes to be monitored by the rotation of the principal strain axis. Reorientation of this axis toward the electric field direction occurred progressively above 0.6 MV m−1, while the angle of rotation increased from 0° to approximately 80° at the maximum field of 3.0 MV m−1. A strong correlation was established between the effective strains associated with different crystallographic directions, which was attributed to the effects of elastic coupling between grains in the polycrystal. [ABSTRACT FROM AUTHOR]

The exploration of the photophysical properties of push–pull molecules incorporating pyrimidine rings as electron-attracting moieties in their structure continues to be a fascinating area of investigation. A thorough examination of these properties not only contributes to fundamental knowledge but also provides crucial insights for the rational design of emissive materials in prospective applications. In this context, this work conducts an in-depth analysis of four families of 4,6-bis(arylvinyl)pyrimidines, evaluating the influence of substituents on both the aryl groups and position 2 of the pyrimidine ring. While previous research has primarily focused on solution studies, this work emphasizes the importance of examining solid-state photophysics. Through a multidisciplinary approach encompassing optical techniques, x-ray diffraction, and quantum chemical calculations, a comprehensive understanding of the structure-property relationships is achieved. This study underscores the intricate interplay between molecular structure, aggregation, and fluorescence behavior in pyrimidines, offering valuable insights with broader implications beyond academic realms. [ABSTRACT FROM AUTHOR]

High energy x-ray pair distribution function measurements show the average coordination number of the first shell in liquid sulfur is 1.86 ± 0.04 across the λ-transition, not precisely 2.0 as widely accepted. This indicates that upon melting, liquid sulfur does not comprise solely of S8 rings but also possesses a significant number of short chains. Intensities of the pre-peak and first diffraction peak of the x-ray structure factor and third peak height of the pair distribution function all show deviations at the λ-transition temperature Tλ, associated with the break-up of S8 rings and the start of oligomer polymerization. A significant number of non-bonded or loosely bonded "interstitial atoms," with an average coordination number of 0.20 ± 0.005, are also observed in the so-called "forbidden zone" between the first and second shells upon melting. The number of interstitial atoms is found to decrease to a minimum at the λ-transition, but the majority persist into the high temperature polymerized liquid. The existence of short chains and nearby interstitial atoms represent the two main factors required to initiate the S8-ring to chain transition, as proposed by recent molecular dynamics simulations. [ABSTRACT FROM AUTHOR]

We attain N-polar and Al-polar AlN thin films on Si(111) substrates by plasma-assisted molecular beam epitaxy. The polarity of AlN epilayers has been validated by wet chemical etching using tetramethylammonium hydroxide and by the direct cross-sectional observation of atomic stacking under high-angle annular dark-field scanning transmission electron microscopy. For the 290 nm-thick as-grown N-polar AlN epilayer, x-ray diffraction (XRD) (002) and (102) ω rocking curve peak full width half maximums (FWHMs) are 475 and 1177 arcsec, and the surface mean square roughness (RMS) is 0.30 nm. We flipped the polarity using the metal-flux-modulation-epitaxy (MME) strategy. The MME strategy promotes anti-phase boundaries (APBs) on the { 2 2 ¯ 01 } crystalline planes instead of commonly observed lateral planar APBs in AlN epilayers. Merging of the tilted APBs at ∼50 nm leads to a complete Al-polar surface. For the 180 nm-thick Al-polar AlN epilayer, XRD (002) and (102) peak FWHMs are 1505 and 2380 arcsec, and the surface RMS is 1.41 nm. Strain analysis by XRD and Raman spectroscopy indicates a uniform tensile strain of 0.160% across the N-polar AlN epilayer surface and a strain distribution of 0.113%–1.16% through the epilayer. In contrast, the Al-polar AlN epilayer exhibits a much broader tensile strain distribution of 0.482%–2.406% along the growth direction, potentially due to the interaction of polarity inversion and strain relaxation. [ABSTRACT FROM AUTHOR]

Using hydrophobic aerogel (AGL) as the carrier, the catalyst supported p-toluene sulfonic acid (p-TSA) is synthesized, and the impact of the hydrophobicity of the catalyst on the formaldehyde–ethylene condensation reaction is investigated. Water contact angle, XRD, N2 adsorption/desorption, IR, and thermogravimetric analysis are used to characterize the catalyst. The outcomes demonstrate the ability of p-TSA to be loaded onto the carrier and the strong hydrophobicity of the catalyst when using AGL as the carrier. The elemental analysis results indicate that when AGL is employed as the carrier, the catalyst not only has more active sites than the SiO2-supported catalyst, but can also effectively limit the loss of active sites, reducing the loss rate from 25.82% to 15.03%. The findings demonstrate that 1,3-dioxane (1,3-DX) had a higher selectivity, rising from 16.2% to 33.3% when using AGL as the carrier. It is discovered that 1,3-propanediol (1,3-PDO) can be directly synthesized with a selectivity of up to 80.5% by employing acetic acid as a solvent in place of water. [ABSTRACT FROM AUTHOR]

The effect of cadmium ions introduced into fluorophosphate glass on the growth and photoluminescence (PL) of the CsPb1–xCdxBr3 perovskite nanocrystals (NCs) is systematically studied. The x-ray diffraction patterns have shown that cadmium ions are really incorporated into the NCs that results in a decrease in the lattice constant from 5.85 (x = 0) to 5.75 Å (x = 0.45). At the large cadmium content in the glass (x > 0.38), simultaneous formation of the perovskite CsPb1–xCdxBr3 NCs and the non-luminescent CsCdBr3 NCs in the hexagonal phase is found. It is also found that the lattice contraction leads to an increase in the bandgap energy and a noticeable shift of the PL band to the blue region of the spectrum (from 2.42 to 2.68 eV) with a drop in quantum yield from 85% for CsPbBr3 NCs down to 4% for CsPb0.55Cd0.45Br3 NCs. It is shown that the PL quantum yield decreases due to the formation of deep trap states, which manifest themselves as a PL band in the energy range of 1.6–2.5 eV at cryogenic temperatures. A simple model explaining the behavior of the PL band as a function of temperature in the range from 30 to 300 K is proposed. [ABSTRACT FROM AUTHOR]

X-ray self-heating is a common by-product of X-ray Free Electron Laser (XFEL) techniques that can affect targets, optics, and other irradiated materials. Diagnosis of heating and induced changes in samples may be performed using the x-ray beam itself as a probe. However, the relationship between conditions created by and inferred from x-ray irradiation is unclear and may be highly dependent on the material system under consideration. Here, we report on a simple case study of a titanium foil irradiated, heated, and probed by a MHz XFEL pulse train at 18.1 keV delivered by the European XFEL using measured x-ray diffraction to determine temperature and finite element analysis to interpret the experimental data. We find a complex relationship between apparent temperatures and sample temperature distributions that must be accounted for to adequately interpret the data, including beam averaging effects, multivalued temperatures due to sample phase transitions, and jumps and gaps in the observable temperature near phase transformations. The results have implications for studies employing x-ray probing of systems with large temperature gradients, particularly where these gradients are produced by the beam itself. Finally, this study shows the potential complexity of studying nonlinear sample behavior, such as phase transformations, where biasing effects of temperature gradients can become paramount, precluding clear observation of true transformation conditions. [ABSTRACT FROM AUTHOR]

The detailed study of the effect of the initial microstructure on its evolution under hydrostatic compression before, during, and after the irreversible α → ω phase transformation and during pressure release in Zr using in situ x-ray diffraction is presented. Two samples were studied: one is plastically pre-deformed Zr with saturated hardness and the other is annealed. Phase transformation α → ω initiates at lower pressure for a pre-deformed sample but for a volume fraction of ω Zr, c > --> 0.7 , a larger volume fraction is observed for the annealed sample. This implies that the proportionality between the athermal resistance to the transformation and the yield strength in the continuum phase transformation theory is invalid; an advanced version of the theory is outlined. Phenomenological plasticity theory under hydrostatic loading is outlined in terms of microstructural parameters, and plastic strain is estimated. During transformation, the first rule is suggested, i.e., the average domain size, microstrain, and dislocation density in ω Zr for c < 0.8 are functions of the volume fraction, c of ω Zr only, which are independent of the plastic strain tensor prior to transformation and pressure. The microstructure is not inherited during phase transformation. Surprisingly, for the annealed sample, the final dislocation density and the average microstrain after pressure release in the ω phase are larger than for the severely pre-deformed sample. The results suggest that an extended experimental basis is required for the predictive models for the combined pressure-induced phase transformations and microstructure evolutions. [ABSTRACT FROM AUTHOR]

In the present work, we have investigated the structural response of transition metal double perovskite oxide Nd 2 CoFeO 6 under pressure by XRD and Raman spectroscopic measurements. From XRD data, we have observed a pressure-induced structural transition from the orthorhombic phase to the monoclinic phase at about 14.8 GPa. An anomalous increase in compressibility at a much lower pressure (∼ 1.1 GPa) is seen where no structural transition occurs. At about the same pressure, a sudden drop in the slope of the Raman shift is observed. Further investigation at low temperatures reveals that the B 1 g Raman mode is strongly affected by magnetic interactions. Additional high-pressure Raman experiments with the application of a magnetic field have indicated that the mentioned anomaly around 1.1 GPa can be explained by a high-spin to low-spin transition of Co 3 + . [ABSTRACT FROM AUTHOR]

We have conducted a detailed high-pressure (HP) investigation on Eu-doped BaTiO3 using angle-resolved x-ray diffraction, Raman spectroscopy, and dielectric permittivity measurements. The x-ray diffraction data analysis shows a pressure-induced structural phase transition from the ambient tetragonal to the mixed cubic and tetragonal phases above 1.4 GPa. The tetragonality of the sample due to the internal deformation of the TiO6 octahedra caused by the charge difference from Eu doping cannot be lifted by pressure. Softening, weakening, and disappearance of low-frequency Raman modes indicate ferroelectric tetragonal to the paraelectric cubic phase transition. However, the pressure-induced increase in the intensity of [E(LO), A1(LO)] and the octahedral breathing modes indicate that the local structural inhomogeneity remains in the crystal and is responsible for spontaneous polarization in the sample. The low-frequency electronic scattering response suggests pressure-induced carrier delocalization, leading to a semi-metallic state in the system. Our HP dielectric constant data can be explained by the presence of pressure-induced localized clusters of microscopic ferroelectric ordering. Our results suggest that the HP phase coexistence leads to a ferroelectric-like semi-metallic state in Eu-doped BaTiO3 under extreme quantum limits. [ABSTRACT FROM AUTHOR]

We have conducted a detailed high-pressure (HP) investigation on Eu-doped BaTiO3 using angle-resolved x-ray diffraction, Raman spectroscopy, and dielectric permittivity measurements. The x-ray diffraction data analysis shows a pressure-induced structural phase transition from the ambient tetragonal to the mixed cubic and tetragonal phases above 1.4 GPa. The tetragonality of the sample due to the internal deformation of the TiO6 octahedra caused by the charge difference from Eu doping cannot be lifted by pressure. Softening, weakening, and disappearance of low-frequency Raman modes indicate ferroelectric tetragonal to the paraelectric cubic phase transition. However, the pressure-induced increase in the intensity of [E(LO), A1(LO)] and the octahedral breathing modes indicate that the local structural inhomogeneity remains in the crystal and is responsible for spontaneous polarization in the sample. The low-frequency electronic scattering response suggests pressure-induced carrier delocalization, leading to a semi-metallic state in the system. Our HP dielectric constant data can be explained by the presence of pressure-induced localized clusters of microscopic ferroelectric ordering. Our results suggest that the HP phase coexistence leads to a ferroelectric-like semi-metallic state in Eu-doped BaTiO3 under extreme quantum limits. [ABSTRACT FROM AUTHOR]

Strain engineering using ion beams is a current topic of research interest in semiconductor materials. Synchrotron-based high-resolution x-ray diffraction has been utilized for strain-depth analysis in GaAs irradiated with 300 keV Ar and 4H-SiC and GaAs irradiated with 100 MeV Ag ions. The direct displacement-related defect formation, anticipated from the elastic energy loss of Ar ions, can well explain the irradiation-induced strain depth profiles. The maximum strain in GaAs is evaluated to be 0.88% after Ar irradiation. The unique energy loss depth profile of 100 MeV Ag (swift heavy ions; SHIs) and resistance of pristine 4H-SiC and GaAs to form amorphous/highly disordered ion tracks by ionization energy loss of monatomic ions allow us to examine strain buildup due to the concentrated displacement damage by the elastic energy loss near the end of ion range (∼ 12 μ m). Interestingly, for the case of SHIs, the strain-depth evolution requires consideration of recovery by ionization energy loss component in addition to the elastic displacement damage. For GaAs, strain builds up throughout the ion range, and the maximum strain increases and then saturates at 0.37% above an ion fluence of 3 × 10 13 Ag/cm 2. For 4H-SiC, the maximum strain reaches 4.6% and then starts to recover for fluences above 1 × 10 13 Ag/cm 2. Finally, the contribution of irradiation defects and the purely mechanical contribution to the total strain have been considered to understand the response of different compounds to ion irradiation. [ABSTRACT FROM AUTHOR]

Temperature dependent bonding behavior plays a significant role in deciding properties of high temperature ceramics like boron carbide. However, few studies to date have addressed the physical properties of this class of materials with respect to their temperature dependent bonding nature. In addition, materials with the flexibility to accommodate variations in interatomic bonding and lattice vibrations over a wide range of temperatures are less known. In this work, temperature dependent structural analyses of carbon-rich boron carbide microflakes using in situ powder x-ray diffraction techniques (up to 1000 °C) supported by transmission electron microscopy measurements reveal that while most bonds in the rhombohedral structure increase in length with temperature; there is no change in certain bond lengths. However, there is an unusual decrease in length (∼1.03%) of the inter-cluster –C–(central boron)BC–C– without any polyhedral redistribution. This is accompanied by an increase in lattice vibrations without significant alteration to the crystal structure over the wide temperature range studied. Temperature dependent micro-Raman experiments further confirmed the above observations. The above bonding behavior could be directly correlated to the trends in reported results of high temperature conductivity via the model of hole hopping through specific atomic positions of the rhombohedral framework, thus opening the scope to investigate structure–property relationships in high temperature functional materials. [ABSTRACT FROM AUTHOR]

Grazing incidence x-ray diffraction reveals that conventional post-deposition-annealed ZrO2 and in situ crystallized (by local epitaxy) ZrO2 thin films (<15 nm) have different internal strain states. A comparison between single- and two-step grown films enables the diverse strain components to be discretely identified. In particular, thickness-dependent intrinsic growth strain is unevenly distributed within the film according to the Volmer–Weber growth. Furthermore, extrinsic thermal strain, locally present in the annealed seed layer, does not spread over the in situ crystallized upper main layer of the two-step film. Post-deposition annealing of the two-step film renders the strain state identical to the single-step films by imposing thermal strain on the in situ crystallized main layer. Local strains created by diffused aluminum and yttrium dopants are also examined. Since each stress factor plays a vital role in the phase formation and electrical behaviors of ZrO2 and other fluorite-structure films, this method will pave the way for understanding the film's internal strain distribution and accompanying performance engineering. [ABSTRACT FROM AUTHOR]

Oxybutynin (Ditropan), a widely distributed muscarinic antagonist for treating the overactive bladder, has been awaiting a definitive crystal structure for ≈50 years due to the sample and technique limitations. Past reports used powder X-ray diffraction (PXRD) to shed light on the possible packing of the molecule however their model showed some inconsistencies when compared with the 2D chemical structure. These are largely attributed to X-ray-induced photoreduction. Here microcrystal electron diffraction (MicroED) is used to successfully unveil the experimental 3D structure of oxybutynin hydrochloride showing marked improvement over the reported PXRD structure. Using the improved model, molecular docking is applied to investigate the binding mechanism between M3 muscarinic receptor (M3R) and (R)-oxybutynin, revealing essential contacts/residues and conformational changes within the protein pocket. A possible universal conformation is proposed for M3R antagonists, which is valuable for future drug development and optimization. This study underscores the immense potential of MicroED as a complementary technique for elucidating unknown pharmaceutical structures, as well as for protein-drug interactions.

In this work, pure and S–N/WO3 (1%–7%) nanoparticles (NPs) have been developed for the degradation of MB dye. Optical properties, vibrational analysis, morphology, structural analysis, and photocatalytic activity of the samples have been evaluated using a variety of characterization techniques, including UV–vis, PL, FTIR, SEM, and x-ray diffraction (XRD). The XRD patterns showed that the stability of the orthorhombic phase of WO3 was affected by the concentrations of S and N. In SEM, nanospheres with an average size of 80 nm of NPs have been observed. The PL results showed that the e−, h+ recombination rate for the S–N7%/WO3 sample was the lowest. The degradation of MB dye has also been investigated in order to investigate the photocatalytic performance. Remarkably, S–N7%/WO3 shows the best results, with a maximum degradation of 90% in 120 min. The stability of the improved catalyst was tested using recycling and trapping studies. S–N7%/WO3 catalyst's exceptional photocatalytic activity highlights its potential use in wastewater treatment. This study will be helpful for manufacturing innovation. [ABSTRACT FROM AUTHOR]

We investigated the spectrum of density fluctuations of a liquid crystal, CB7CB, in two different orientations by using high-resolution inelastic x-ray scattering. Our analysis, based on Bayesian principles, revealed that high-frequency collective excitations propagate through this mesoscale-ordered sample in a peculiar manner that lies somewhere between those observed in liquids and crystalline systems. Interestingly, when we probed longer length scales, a more pronounced solid-like response emerged. This was mainly characterized by anomalously sharp inelastic excitations and the onset of shear mode propagation. Comparison with previous x-ray diffraction results suggests a correlation between the observed behavior and the mesogen arrangement. [ABSTRACT FROM AUTHOR]

Position-dependent three-dimensional reciprocal space mapping (RSM) by nanobeam x-ray diffraction (nanoXRD) was performed to reveal the strain fields produced around individual threading dislocations (TDs) in GaN substrates. The distribution and Burgers vector of TDs for the nanoXRD measurements were confirmed by prerequisite analysis of multi-photon excited photoluminescence and etch pit methods. The present results demonstrated that the nanoXRD can identify change in the lattice plane structure for all types of TDs, i.e., edge-, screw-, and mixed TDs with the Burgers vector of b = 1a, 1c and 1m + 1c. Strain tensor components related to edge and/or screw components of the TDs analyzed from the three-dimensional RSM data showed a nearly symmetrical strained region centered on the TD positions, which were in good agreements with simulation results based on the isotropic elastic theory using a particular Burgers vector. The present method is beneficial in that it allows non-destructive analysis of screw components of TDs that tend to contribute to leakage characteristics and are not routinely accessible by conventional structural analysis. These results indicate that nanoXRD could be a powerful way to reveal three-dimensional strain fields associated with arbitrary types of TDs in semiconductor materials, such as GaN and SiC. [ABSTRACT FROM AUTHOR]

Ethane ( C 2 H 6 ) is anticipated to be the most stable compound within the carbon–hydrogen system under the 100 GPa pressure range. Nevertheless, the properties of ethane under pressure are still poorly documented. Here, we present a comprehensive study of the structural and vibrational properties of C 2 H 6 in a diamond anvil cell at pressures up to 150 GPa. To obtain detailed data, ethane single-crystal was grown in a helium pressure-transmitting medium. Utilizing single-crystal x-ray diffraction, the distortion mechanism between the tetragonal and monoclinic phases, occurring over the 3.2–5.2 GPa pressure range, is disclosed. Subsequently, no phase transition is observed up to 150 GPa. The accurately measured compression curve is compared to various computational approximations. The vibrational modes measured by Raman spectroscopy and infrared absorption are well identified, and their evolution is well reproduced by ab initio calculations. In particular, an unusual anticrossing phenomenon occurs near 40 GPa between a rocking and a stretching mode, likely attributable to intermolecular interactions through hydrogen bonding. [ABSTRACT FROM AUTHOR]

In this study, phase transitions (structural and magnetic) and associated magnetocaloric properties of stoichiometric MnCoGe have been investigated as a function of annealing pressure. Metastable phases were generated by annealing at 800 ° C followed by rapid cooling under pressures up to 6.0 GPa. The x-ray diffraction results reveal that the crystal cell volume of the metastable phases continuously decreases with increasing thermal processing pressure, leading to a decrease in the structural transition temperature. The magnetic and structural transitions merge and form a first-order magnetostructural transition between the ferromagnetic orthorhombic and paramagnetic hexagonal phases over a broad temperature range (>80 K) spanning room temperature, yielding considerable magnetic entropy changes. These findings demonstrate the utility of thermal processing under high pressure, i.e., high-pressure annealing, to control the magnetostructural transitions and associated magnetocaloric properties of MnCoGe without altering its chemical composition. [ABSTRACT FROM AUTHOR]

Ion hydration plays a crucial role in numerous fundamental processes. Various spectroscopic methods are employed to investigate the slowing down of hydration bond dynamics in the proximity of both anions and cations. To date, most of these studies have primarily focused on the properties of binary systems. However, in comparison to ion–water binary systems, ternary systems that involve ions, water, and organic matter are more prevalent in nature and provide more realistic insights into biological processes. This study focuses on ion hydration in water and alcohol mixture using terahertz spectroscopy and x-ray diffraction (XRD). The results reveal a distinct behavior depending on the type of alcohol used. Specifically, the presence of both methanol and ethanol results in the disappearance of absorption peaks associated with NaCl hydrate at low temperatures. In contrast, tert-butanol does not exhibit such an effect, and isopropanol demonstrates a more complex response. By combining these terahertz spectroscopic findings with low-temperature XRD data, we gain insights into the formation, or lack thereof, of NaCl · 2H2O hydrate crystals. Crucially, our observations suggest a dominant correlation between the polarity of the alcohol molecules and its impact on the Na+ hydration. Strongly polar alcohols preferentially solvating the Na+ ion lead to the failure of hydrate formation, while weakly polar alcohols do not have this effect. [ABSTRACT FROM AUTHOR]

GaOx devices have been extensively explored for applications such as power devices and solar blind detectors, based on their wide bandgap. In this study, we investigated the synaptic properties of the amorphous gallium oxide (a-GaOx)- based memristor with a W/WOx/a-GaOx/ITO structure, in which a-GaOx are deposited by RF magnetic sputtering at ambient temperature. The structure and components of a-GaOx are characterized by XRD, XPS, SEM, and EDS. The electrical test indicates that W/WOx/a-GaOx is ohmic due to the thin WOx layer with a high concentration of oxygen vacancies. Consequently, the synaptic characteristics of the W/WOx/a-GaOx/ITO memristor depend on both the a-GaOx layer itself and the a-GaOx/ITO junction. The fitting results indicate that the a-GaOx/ITO junction is Schottky with unidirectional conductive properties. However, the elevated defect density results in a larger current for the reverse-biased a-GaOx/ITO junction. Moreover, adjusting the thickness of a-GaOx allows the device to achieve almost symmetrical forward and reverse currents. We have successfully observed typical synaptic characteristics in W/WOx/a-GaOx/ITO when stimulated by consecutive spike signals. Clearly, through careful design considerations regarding the structure and parameters, we have realized superior synaptic performance in a-GaOx-based memristors. This achievement shows that amorphous GaOx has great potential applications in neuromorphic computation chips for artificial intelligence or the Internet of Things in the future. [ABSTRACT FROM AUTHOR]

The present study focuses on the oxygen (O)-ion implantation-induced structural and electronic modifications in the single crystals of strontium-titanate (s-STO) using synchrotron-based x-ray diffraction (XRD), x-ray photoemission spectroscopy (XPS), and resonant x-ray photoemission spectroscopy. The crystallinity of the epitaxially aligned phases of s-STO is confirmed through XRD. This direct evidence of heavy ion implantation is supported by the Monte Carlo-based simulation of stopping and range of ions in matter/transport of ions in matter. XPS at different core levels is performed to detect the exact oxidation state of Ti ions in s-STO. The dominance of Ti3+ over Ti4+ upon oxygen implantation suggests the disorder in the perovskite material, primarily in the form of oxygen vacancies (VO). The confirmation of VO is explicitly shown by the enhancement in the spectral area of the assigned peak in the O 1s XPS. Resonant photoemission spectroscopy measurements were performed by varying photon energy from 32 to 46 eV to understand the nature of the valence band electronic structure of s-STO. The resonance in the different hybridized states of s-STO is confirmed by the spectral features of constant initial state plots. There is a correlation between the defective state of Ti and the oxygen-deficient state. The transformation from SrTiO3 to SrTiO2.5, partially or completely, is essentially required to underline any modification in the electronic properties of s-STO. s-STO is in a mixed state of an ionic conductor and an electronic conductor. This study outlines the creation of VO due to O-ion implantation and investigates the changes in the electronic structures of s-STO. [ABSTRACT FROM AUTHOR]

Drug discovery relies on efficient identification of small-molecule leads and their interactions with macromolecular targets. However, understanding how chemotypes impact mechanistically important conformational states often remains secondary among high-throughput discovery methods. Here, we present a conformational discovery pipeline integrating time-resolved, high-throughput small-angle X-ray scattering (TR-HT-SAXS) and classic fragment screening applied to allosteric states of the mitochondrial import oxidoreductase apoptosis-inducing factor (AIF). By monitoring oxidized and X-ray-reduced AIF states, TR-HT-SAXS leverages structure and kinetics to generate a multidimensional screening dataset that identifies fragment chemotypes allosterically stimulating AIF dimerization. Fragment-induced dimerization rates, quantified with time-resolved SAXS similarity analysis (kVR), capture structure-activity relationships (SAR) across the top-ranked 4-aminoquinoline chemotype. Crystallized AIF-aminoquinoline complexes validate TR-SAXS-guided SAR, supporting this conformational chemotype for optimization. AIF-aminoquinoline structures and mutational analysis reveal active site F482 as an underappreciated allosteric stabilizer of AIF dimerization. This conformational discovery pipeline illustrates TR-HT-SAXS as an effective technology for targeting chemical leads to important macromolecular states.

The molecular foundations of epidermal cell wall mechanics are critical for understanding structure-function relationships of primary cell walls in plants and facilitating the design of bioinspired materials. To uncover the molecular mechanisms regulating the high extensibility and strength of the cell wall, the onion epidermal wall is stretched uniaxially to various strains and cell wall structures from mesoscale to atomic scale are characterized. Upon longitudinal stretching to high strain, epidermal walls contract in the transverse direction, resulting in a reduced area. Atomic force microscopy shows that cellulose microfibrils exhibit orientation-dependent rearrangements at high strains: longitudinal microfibrils are straightened out and become highly ordered, while transverse microfibrils curve and kink. Small-angle X-ray scattering detects a 7.4 nm spacing aligned along the stretch direction at high strain, which is attributed to distances between individual cellulose microfibrils. Furthermore, wide-angle X-ray scattering reveals a widening of (004) lattice spacing and contraction of (200) lattice spacing in longitudinally aligned cellulose microfibrils at high strain, which implies longitudinal stretching of the cellulose crystal. These findings provide molecular insights into the ability of the wall to bear additional load after yielding: the aggregation of longitudinal microfibrils impedes sliding and enables further stretching of the cellulose to bear increased loads.

Grazing-incidence x-ray diffraction (GIXRD) is a scattering technique that allows one to characterize the structure of fluid interfaces down to the molecular scale, including the measurement of surface tension and interface roughness. However, the corresponding standard data analysis at nonzero wave numbers has been criticized as to be inconclusive because the scattering intensity is polluted by the unavoidable scattering from the bulk. Here, we overcome this ambiguity by proposing a physically consistent model of the bulk contribution based on a minimal set of assumptions of experimental relevance. To this end, we derive an explicit integral expression for the background scattering, which can be determined numerically from the static structure factors of the coexisting bulk phases as independent input. Concerning the interpretation of GIXRD data inferred from computer simulations, we extend the model to account also for the finite sizes of the bulk phases, which are unavoidable in simulations. The corresponding leading-order correction beyond the dominant contribution to the scattered intensity is revealed by asymptotic analysis, which is characterized by the competition between the linear system size and the x-ray penetration depth in the case of simulations. Specifically, we have calculated the expected GIXRD intensity for scattering at the planar liquid–vapor interface of Lennard-Jones fluids with truncated pair interactions via extensive, high-precision computer simulations. The reported data cover interfacial and bulk properties of fluid states along the whole liquid–vapor coexistence line. A sensitivity analysis shows that our findings are robust with respect to the detailed definition of the mean interface position. We conclude that previous claims of an enhanced surface tension at mesoscopic scales are amenable to unambiguous tests via scattering experiments. [ABSTRACT FROM AUTHOR]

We report an enhanced magnetoelectric (ME) effect in spin–phonon coupled single-phase La1−xSmxYFe2O6 (0 ≤ x ≤ 1). The structural, electric, magnetic, and ME properties have been investigated to establish their interplay leading to magnetoelectricity. X-ray diffraction study suggests the facilitation of the P21nm phase (double perovskite lattice arrangements) formation and improved structural order due to the substitution of Sm in the lattice. Antiferromagnetic (AFM) transition ∼700 K along with a spin-reorientation transition around room temperature (RT) and below is observed in the thermomagnetic curve. The indication of short range ordering in the magnetization data in the form of a non-Griffiths-like phase (nGP) is observed. The short range ordering could be minimized along with consequent improvement in AFM ordering, due to Sm substitution. An enhanced (∼31% with respect to x = 0) RT first-order ME coupling coefficient ∼0.59 mV cm−1 Oe−1 in x = 0.75 composition is observed. The findings reported here open the door to exercise spin-reorientation transition in the spin–phonon coupled double perovskites for spintronic device applications. [ABSTRACT FROM AUTHOR]

We report an enhanced magnetoelectric (ME) effect in spin–phonon coupled single-phase La1−xSmxYFe2O6 (0 ≤ x ≤ 1). The structural, electric, magnetic, and ME properties have been investigated to establish their interplay leading to magnetoelectricity. X-ray diffraction study suggests the facilitation of the P21nm phase (double perovskite lattice arrangements) formation and improved structural order due to the substitution of Sm in the lattice. Antiferromagnetic (AFM) transition ∼700 K along with a spin-reorientation transition around room temperature (RT) and below is observed in the thermomagnetic curve. The indication of short range ordering in the magnetization data in the form of a non-Griffiths-like phase (nGP) is observed. The short range ordering could be minimized along with consequent improvement in AFM ordering, due to Sm substitution. An enhanced (∼31% with respect to x = 0) RT first-order ME coupling coefficient ∼0.59 mV cm−1 Oe−1 in x = 0.75 composition is observed. The findings reported here open the door to exercise spin-reorientation transition in the spin–phonon coupled double perovskites for spintronic device applications. [ABSTRACT FROM AUTHOR]

In this report, the high-temperature transport properties of (Dy1−xCax)(Zr0.2Hf0.2Sn0.2Ti0.2Ge0.2)O7 pyrochlore oxides with x = 0, 0.05, and 0.1 are studied in dry and humid air. The phase composition and crystal structure were determined by using x-ray and neutron diffraction. The addition of calcium to the structure caused an increase in the concentration of oxygen vacancies, indicating an ionic charge compensation mechanism. Electrical studies allowed us to determine the total electrical conductivity as a function of the synthesis atmosphere and pH2O. The electrical conductivity turned out to be at the level of ∼10−3 S/cm at 800 °C, and only a slight effect of the presence of protonic defects in the structure on the total electrical conductivity was observed. In general, the samples had a low electrical conductivity with a relatively high activation energy of conduction. [ABSTRACT FROM AUTHOR]

Nanowires (NWs) composed of 2,4-bis[(4-diethylamino)-2-hydroxyphenyl] squaraine were prepared by evaporation-induced self-assembly (EISA). NWs were ∼560 nm wide (aspect ratios: 10–90). X-ray diffraction analysis indicated polymorphism (monoclinic/triclinic). Optical data reported the triclinic phase with energetic disorder. Given the favorable alignment of the Au work function and squaraine HOMO energy, symmetric, unipolar metal–insulator–metal devices were formed by the EISA of NW meshes on inter-digitated Au electrodes. Room temperature DC I–V characteristics displayed hysteretic I–V loops, indicating memristive behavior. At low bias, data indicated Ohmic transport with carrier extraction facilitated by thermionic emission. At high biases, devices exhibited space-charge-limited conduction in the presence of shallow traps. At 77 K, data indicated Ohmic transport at low bias with carrier extraction by thermionic emission while, at high biases, trap-limited space-charge-limited conduction in the presence of traps distributed in energy, with carrier extraction by Fowler–Nordheim tunneling, was observed. The I–V hysteresis was eliminated at 77 K and attenuated by fast scan rates at room temperature, suggesting that carrier trapping/de-trapping underpinned the hysteresis. In impedance measurements, the device response fitted a Randles equivalent circuit indicating purely electronic conduction. By applying voltage waveforms, I–V hysteresis and analog resistive switching (memristive) functionality were observed. Device conductance could be increased sweep by sweep, giving conductance tuning through distinct states, with wait time- or voltage-erase options, consistent with trap filling/emptying effects. Repeated erase–write–read of multiple distinct states over many voltage cycles during continuous use in air was demonstrated. Finally, synaptic functions, e.g., pulse-dependent plasticity, and short- to long-term memory transition, were successfully emulated. [ABSTRACT FROM AUTHOR]

The effect of the GaAsP strain-compensating layer on type-II GaAs1−xSbx/InyGa1−yAs was investigated. GaAsSb/InGaAs multiple quantum wells (MQWs) without and with GaAsP strain-compensating layers were grown by molecular beam epitaxy. Increasing Sb or In compositions can extend photoluminescence (PL) emission at longer wavelength along with the highly induced compressive strain in the QWs. The power-dependent PL measured at low temperature reveals the type-II band characteristics of the GaAs1−xSbx/InyGa1−yAs system. A detailed analysis of the experimental data reveals that the GaAsP layers compensate the compressive strain of GaAsSb/InGaAs. The type-II QWs with GaAsP layers, (8 nm) GaAs0.84Sb0.16/(2.5 nm) In0.3Ga0.7As/(10 nm) GaAs0.85P0.15, emits PL at ∼1.1 μm, up to 210 K, while the PL of those strained sample without GaAsP vanishes at lower temperature. In view of the described sample, x-ray diffraction (XRD) analysis along with the simulation shows the validity of the procedure, resulting in nearly matched parameters of QW thicknesses and material compositions—(8.9 nm) GaAs0.835Sb0.165/(2.3 nm) In0.3Ga0.7As/(10.3 nm) GaAs0.85P0.15, with those of the designed QW. The thicknesses of QW from the TEM image, (8.6 nm) GaAsSb/(3.1 nm) InGaAs/(10.1 nm) GaAsP, agree well with the XRD results. [ABSTRACT FROM AUTHOR]

The ability to study chemical dynamics on ultrafast timescales has greatly advanced with the introduction of X-ray free electron lasers (XFELs) providing short pulses of intense X-rays tailored to probe atomic structure and electronic configuration. Fully exploiting the full potential of XFELs requires specialized experimental endstations along with the development of techniques and methods to successfully carry out experiments. The liquid jet endstation (LJE) at the Linac Coherent Light Source (LCLS) has been developed to study photochemistry and biochemistry in solution systems using a combination of X-ray solution scattering (XSS), X-ray absorption spectroscopy (XAS), and X-ray emission spectroscopy (XES). The pump-probe setup utilizes an optical laser to excite the sample, which is subsequently probed by a hard X-ray pulse to resolve structural and electronic dynamics at their intrinsic femtosecond timescales. The LJE ensures reliable sample delivery to the X-ray interaction point via various liquid jets, enabling rapid replenishment of thin samples with millimolar concentrations and low sample volumes at the 120 Hz repetition rate of the LCLS beam. This paper provides a detailed description of the LJE design and of the techniques it enables, with an emphasis on the diagnostics required for real-time monitoring of the liquid jet and on the spatiotemporal overlap methods used to optimize the signal. Additionally, various scientific examples are discussed, highlighting the versatility of the LJE.

Tungstates and molybdates possessing the scheelite- and wolframite-type (if present) structures hold a significant functional value. Their high-pressure phase diagrams are very complicated and controversial, and even some parts have not been characterized yet. In this study, we investigate the sequence of pressure driven structural phase transitions up to 100 GPa in these tungstate and molybdate families via first-principles structure predictions. Based on our structural predictions, it is possible for isostructural tungstates and molybdates to exhibit a phase transition sequence that is either similar or identical. Examples of these compounds are CaWO4, CaMoO4, and CdMoO4, in addition to EuWO4 and EuMoO4. However, the phase transition sequences of some tungstates and molybdates, especially those with different divalent cations, display noteworthy variations, revealing the intricate influence of ionic radii and electronic properties on crystal configurations. To obtain a deeper understanding of the high-pressure phase transition behavior of tungstates and molybdates, we analyze the high-pressure phase diagrams of MgWO4, SrWO4, and CaMoO4, representative examples of wolframite-type tungstate, scheelite-type tungstate, and scheelite-type molybdate, respectively, using x-ray powder diffraction. Our x-ray diffraction experiments and structure predictions consistently verify that the orthorhombic Cmca phase is a high-pressure phase of SrWO4. Structural configurations and mechanical properties of these predicted structures are discussed, and electronic properties are given. This study could have important implications for the fields of seismology and geophysics, as well as the utilization of these materials in various capacities, such as photocatalysts, photoanodes, and phosphors. [ABSTRACT FROM AUTHOR]

Silicene, a 2D hexagonal structure of silicon, has shown great promise for next-generation advanced electronic devices due to recent progress. However, one major obstacle to its application and integration into devices is its strong tendency of rapid oxidation in an ambient environment. Enhancing the chemical inertness by means of chemical modification without comprising its unique structure and properties is vital. Here, we report the fabrication of hydrogenated silicene grown on polycrystalline Ag films by means of plasma-enhanced chemical-vapor deposition (PECVD) with proper hydrogen dilution. Our Raman spectroscopy and x-ray diffraction results show the existence of typical monolayer and few-layer silicene. The x-ray photoelectron spectroscopy demonstrates its oxidation resistance after a few minutes of air exposure in a class 100 clean room. We propose that PECVD silicene can be an alternative to molecular-beam-epitaxy silicene for potential low-cost and large-area silicene applications. [ABSTRACT FROM AUTHOR]

Here, we present a new approach for obtaining radial distribution functions (RDF) from the electron diffraction data using a regularized weighted sine least-squares spectral analysis. It allows for explicitly transferring the measured experimental uncertainties in the reduced molecular scattering function to the produced RDF. We provide a numerical demonstration, discuss the uncertainties and correlations in the RDFs, and suggest a regularization parameter choice criterion. The approach is also applicable for other diffraction data, e.g., for x-ray or neutron diffraction of liquid samples. [ABSTRACT FROM AUTHOR]

1-propanol/water mixtures over the whole composition range (0 < XV ≤ 1; XV is the 1-propanol volume fraction) are shown to be structurally and dynamically heterogeneous. By combining structural (x-ray diffraction), thermodynamic (differential scanning calorimetry) and dynamical probes (dielectric spectroscopy) we construct the pertinent phase diagram. It consists of liquid 1-propanol, liquid water, hexagonal ice and different hydrates, the latter sharing the same lattice. The phase diagram can be discussed in terms of four regimes, all having in common a droplet arrangement of the minority component. When water droplets are strongly confined by 1-propanol (regime I, 0.92 < XV ≤ 1; "soft" confinement), water is unable to crystallize. It has dynamics reminiscent to the ultra-viscous water phase known as high-density liquid (HDL). When water droplets are moderately confined (regime II, 0.75 < XV ≤ 0.92) water can crystallize via homogeneous nucleation. Strikingly, the homogeneous nucleation temperature is at 205 K, well within "no-man's land." The result is in line with earlier reports that soft confinement is the key to enter into the "no-man's land". When 1-propanol is the minority component (regimes III and IV), the structure and the dynamics are dominated by the 1-propanol/water interface with the formation of hydrates. The corresponding dynamical features suggest a link between hydrate formation and the two metastable phases of ultra-viscous water, HDL and low-density liquid. [ABSTRACT FROM AUTHOR]

In situ temperature-dependent crystal structure of lead-free ferroelectric perovskite Ba0.798Ca0.202Zr0.006Ti0.994O3 single crystal was characterized using x-ray diffraction from 170 to 380 K. Three phases were identified at different temperatures of 170, 220, and 298 K, revealing rhombohedral (R3m), orthorhombic (Pmm2), and tetragonal (P4mm) crystal structures, respectively. The change in the bond length and its distortion are reported for both AO12 and BO6 polyhedrons, allowing for the estimation of the spontaneous polarization. The Debye–Waller factor is reported as a function of temperature for A and B-sites. Density-functional theory calculations on the tetragonal phase were performed to obtain information on the distribution of the Ca ions, the local atomic displacements, and the ideal value of the spontaneous polarization of a defect-free crystal at 0 K. We find that Ca prefers to arrange in columnar 2D plates oriented along the tetragonal axis. The Ca ions avoid being next neighbors of Zr; however, the specific arrangement of Ca has only a minor impact on the spontaneous polarization. [ABSTRACT FROM AUTHOR]

Transition-metal and rare-earth borides are of considerable interest due to their electronic, mechanical, and magnetic properties as well as their structural stability under extreme conditions. Here, we report on a series of high-pressure Raman and x-ray diffraction experiments on the cubic rare-earth hexaboride EuB6 to an ultrahigh pressure of 187 GPa in a diamond anvil cell. In EuB6, divalent europium ions occupy the corners of the cubic structure, which encloses a rigid boron-bonded cage. So far, no structural phase transitions have been reported, while the nanoindentation studies indicate amorphization in nanoscale shear bands during plastic deformation. Our x-ray diffraction studies have revealed that the ambient cubic phase of EuB6 shows broadening and splitting of diffraction peaks starting at 72 GPa and the broadening continuing to 187 GPa. The high-pressure phase is recovered on decompression, and the Raman spectroscopy of the recovered sample from 187 GPa shows a downward frequency shift and broadening of T2g, Eg, and A1g modes of boron octahedron. The density functional theory simulations of EuB6 at 100 GPa have identified five possible lowest energy crystal structures. The experimental x-ray diffraction data at high pressures is compared with the theoretical predictions and the role of structural distortions induced by shear stresses is also discussed. [ABSTRACT FROM AUTHOR]

The axon-initial-segment (AIS) of mature neurons contains microtubule (MT) fascicles (linear bundles) implicated as retrograde diffusion barriers in the retention of MT-associated protein (MAP) tau inside axons. Tau dysfunction and leakage outside of the axon is associated with neurodegeneration. We report on the structure of steady-state MT bundles in varying concentrations of Mg2+ or Ca2+ divalent cations in mixtures containing αβ-tubulin, full-length tau, and GTP at 37 °C in a physiological buffer. A concentration-time kinetic phase diagram generated by synchrotron SAXS reveals a wide-spacing MT bundle phase (Bws), a transient intermediate MT bundle phase (Bint), and a tubulin ring phase. SAXS with TEM of plastic-embedded samples provides evidence of a viscoelastic intervening network (IN) of complexes of tubulin oligomers and tau stabilizing MT bundles. In this model, αβ-tubulin oligomers in the IN are crosslinked by taus MT binding repeats, which also link αβ-tubulin oligomers to αβ-tubulin within the MT lattice. The model challenges whether the cross-bridging of MTs is attributed entirely to MAPs. Tubulin-tau complexes in the IN or bound to isolated MTs are potential sites for enzymatic modification of tau, promoting nucleation and growth of tau fibrils in tauopathies.

Abstract: The crystal structure and bonding environment of K2Ca(CO3)2 bütschliite were probed under isothermal compression via Raman spectroscopy to 95 GPa and single crystal and powder X-ray diffraction to 12 and 68 GPa, respectively. A second order Birch-Murnaghan equation of state fit to the X-ray data yields a bulk modulus, $${K}_{0}=46.9$$ K 0 = 46.9 GPa with an imposed value of $${K}_{0}^{\prime}= 4$$ K 0 ′ = 4 for the ambient pressure phase. Compression of bütschliite is highly anisotropic, with contraction along the c-axis accounting for most of the volume change. Bütschliite undergoes a phase transition to a monoclinic C2/m structure at around 6 GPa, mirroring polymorphism within isostructural borates. A fit to the compression data of the monoclinic phase yields $${V}_{0}=322.2$$ V 0 = 322.2  Å3$$,$$ , $${K}_{0}=24.8$$ K 0 = 24.8 GPa and $${K}_{0}^{\prime}=4.0$$ K 0 ′ = 4.0 using a third order fit; the ability to access different compression mechanisms gives rise to a more compressible material than the low-pressure phase. In particular, compression of the C2/m phase involves interlayer displacement and twisting of the [CO3] units, and an increase in coordination number of the K+ ion. Three more phase transitions, at ~ 28, 34, and 37 GPa occur based on the Raman spectra and powder diffraction data: these give rise to new [CO3] bonding environments within the structure.

Electron bifurcation (BF) is an evolutionarily ancient energy coupling mechanism in anaerobes, whose associated enzymatic machinery remains enigmatic. In BF-flavoenzymes, a chemically high-potential electron forms in a thermodynamically favorable fashion by simultaneously dropping the potential of a second electron before its donation to physiological acceptors. The cryo-EM and spectroscopic analyses of the BF-enzyme Fix/EtfABCX from Thermotoga maritima suggest that the BF-site contains a special flavin-adenine dinucleotide and, upon its reduction with NADH, a low-potential electron transfers to ferredoxin and a high-potential electron reduces menaquinone. The transfer of energy from high-energy intermediates must be carefully orchestrated conformationally to avoid equilibration. Herein, anaerobic size exclusion-coupled small-angle X-ray scattering (SEC-SAXS) shows that the Fix/EtfAB heterodimer subcomplex, which houses BF- and electron transfer (ET)-flavins, exists in a conformational equilibrium of compacted and extended states between flavin-binding domains, the abundance of which is impacted by reduction and NAD(H) binding. The conformations identify dynamics associated with the T. maritima enzyme and also recapitulate states identified in static structures of homologous BF-flavoenzymes. Reduction of Fix/EtfABCX's flavins alone is insufficient to elicit domain movements conducive to ET but requires a structural "trigger" induced by NAD(H) binding. Models show that Fix/EtfABCX's superdimer exists in a combination of states with respect to its BF-subcomplexes, suggesting a cooperative mechanism between supermonomers for optimizing catalysis. The correlation of conformational states with pathway steps suggests a structural means with which Fix/EtfABCX may progress through its catalytic cycle. Collectively, these observations provide a structural framework for tracing Fix/EtfABCX's catalysis.

The present study reports a fast and efficient chemical decontamination of water using a tree-branched centimetre-scale microfluidic reactor where zinc oxide nanowires (ZnONWs) act as a photocatalyst. Direct growth of ZnONWs on a silicon wafer with a surface of 1.5 × 1.5 cm2 within the microfluidic chamber brings this photocatalytic medium at the very close vicinity of the water flow path, hence minimising the required interaction time to produce efficient purification performance. The phase and the composition of ZnONWs were characterised by XRD and showing an excellent crystallinity. The microreactor consists of two dendritic microchannels for fluid input/output with a chamber volume 30 μl. The performance of microreactor was evaluated by measuring one-pass ibuprofen (IBP) removal yield. It is shown that the IBP concentration changes over time and increased from 25% to 97% with decreasing the IBP concentration. ZnONWs show excellent photocatalytic IBP degradation efficiency (>99%) under UV light in less than 60 seconds in one pass. Therefore, the high surface/volume ratio would significantly improve the mass transfer efficiency. To describe the kinetics of photocatalytic reaction, the model of Langmuir-Hinshelwood is applied in the form of a pseudo first-order model. [ABSTRACT FROM AUTHOR]

Clean water is essential to our health, community and economy, but also its availability remains a major challenge even today. Graphene oxide membranes have shown significant promise in addressing this problem. A great deal of research has been conducted and is still being done to produce a stable graphene oxide membrane with high permeability and rejection rate. In this study, a highly stable GO membrane was fabricated using a simple vacuum filtration technique by the addition of TRIS and PEG. This is the first paper to discuss the potential for this combination to remove dyes and how it can result in the formation of a stable membrane. The membranes were characterised in detail using various characterisation techniques such as XRD, XPS, AFM, etc., and their ability in dye removal was investigated using UV–Vis spectroscopy. The stability of the developed membranes was tested using ultrasonication, and it was found that the membranes could remove the organic dyes (MB and CR) even at high concentration of dye (20 ppm) and with rejection percentage of 95% for both dyes. Furthermore, the membranes showed good water permeability with a value of 183 Lm−2h−1bar −1 emphasising its high potential for water purification. [ABSTRACT FROM AUTHOR]

The comparison between natural and synthetic composites based on molybdate for the sorption and separation of Gd(III) from Eu(III) and Y(III) was studied. Calcium magnesium molybdate (CaMgMo) and dolomite molybdate (dolomite-Mo) composites have been prepared using the co-precipitation technique and characterised using different analytical tools such as XRD, ATR, SEM, TGA and DTA. The sorption studies applied on Gd(III), Eu(III) and Y(III) by batch technique include the effect of shaking time and pH on sorption efficiency. The data reveal that CaMgMo has higher sorption efficiency than the dolomite-Mo composite at all times and pH values. The distribution coefficients at different pHs have order: Gd(III)>>Eu(III)>Y(III) on both prepared composites. The saturation capacity of two prepared composites towards studied cations has sequence order; Gd(III) >> Eu(III) > Y(III). Reaction kinetics obeys the pseudo-2nd-order model. Binary and tertiary systems data confirm that the CaMgMo composite has high separation factors for Gd(III) at different pHs. The real sample applications prove that CaMgMo and dolomite-Mo are excellent composites for the capture of Gd(III) and Y(III) from high-grade monazite (HGM). [ABSTRACT FROM AUTHOR]

Restricted biodegradability, toxicity, and carcinogenicity of basic fuchsin dye are the principal reasons that motivate scientists to find methods to remove it. Photocatalytic degradation technology is simple, environmentally friendly, inexpensive, efficient, and does not yield secondary pollution. Most of the catalysts used to degrade basic fuchsin dye require expensive chemicals to prepare. Therefore, the novelty in our work comes from the utilisation of low-cost chemicals for the facile synthesis of Mn0.5Zn0.5Fe2O4/Fe2O3 nanocomposite using the pechini sol-gel method. The synthesised samples at 300, 600, and 900°C were encoded as F300, F600, and F900, respectively. The XRD confirmed that the average crystallite size of the F300, F600, and F900 samples is 95.08, 122.32, and 160.21 nm, respectively. Hence, as the calcination temperature increases, the crystallite size increases as a result of coagulation that occurs at higher temperatures. The FE-SEM images showed that the F300, F600, and F900 samples consist of spherical, (polyhedral and spherical), and (hexagonal and spherical) shapes with an average diameter of 258.64, 470.12, and 625.32 nm, respectively. This change in morphology at different temperatures is due to the discrepancy in the rate of liberation of organic matter at different temperatures. In the presence of hydrogen peroxide, 0.05 g of the Mn0.5Zn0.5Fe2O4/Fe2O3 nanocomposite degrade 100% of 25 mL of 25 mg/L of basic fuchsin dye at pH = 8 within 25 min. Consequently, the other side of the novelty of our work is the ability of the synthesised nanocomposite to effectively degrade a high concentration of the basic fuchsin dye in a short time. [ABSTRACT FROM AUTHOR]

Herein, we report the synthesis, characterisation and glucose sensor study of prepared compounds and composite. The prepared samples reported here for glucose-sensing applications were doped (Mn.NiO) and un-doped metal oxide (NiO) and their composite with 2D layered material (Mn-doped-NiO/rGO). The structural analysis of the samples was done by conventional technique called as X-rays diffraction (×RD). Spectral and functional groups' analysis was elucidated by FTIR spectroscopy. The electron microscopy (SEM) was used for morphological features study. The electrochemical measurements were carried out to analyse biosensing response. Carbon fibre cloth was used as a substrate material to fabricate Mn-doped-NiO/rGO nanocomposite-based biosensor for glucose detection. The analytical performance of the synthesised material was evaluated in terms of electrochemical sensitivity, linear response and limit of detection (LOD). The results showed that the material exhibited an excellent electrochemical sensitivity towards glucose detection with wider range of linear responses. The LOD for Mn-doped-NiO/rGO nanocomposite was 0.11 µM, regression equation for the low concentration was I(µA) = 1477.1C + 165.19 with correlation coefficient value R2 = 0.9849. Conclusively, the rGO-based Mn-doped-NiO nanocomposite experienced robust potential as non-enzymatic sensor for detection of glucose. [ABSTRACT FROM AUTHOR]

Chitosan-magnetite nanocomposite (CM) was synthesised using the one-step procedure, reducing the synthesis time and the complexity of the process. The synthesized CM was characterised by using X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), Brunauer-Emmett-Teller (BET), vibrating sample magnetometer (VSM). The nanocomposite was used to remove eriochrome black T (EBT) from the aqueous solution. The effects of pH, adsorption time, initial concentration of EBT, dose, and temperatures were studied. The experiment data were analysed by pseudo-first-order, pseudo-second-order, Elovich, and intra-particle-diffusion kinetic models. Among these models, the pseudo-second-order was the best fit model and the adsorption rate constant of EBT was 0.007 g/mg.min. The adsorption isotherms were studied by fitting the experimental data to the Langmuir, Freundlich, and Temkin models. The results indicated that the Langmuir model was the fittest model for describing the isotherms of the EBT adsorption on CM. When the temperature increased from 293 to 313K, the maximum adsorption capacity of EBT decreased from 291.2 to 83.5 mg/g. The thermodynamic study showed that the ETB adsorption process onto CM was a spontaneous and exothermic process with ∆G0, ∆H0 negative. The EBT dye adsorption mechanism was discussed, involved interactions, such as electrostatic attraction and H-bonding. CM could be regenerated and reused to adsorb anionic dye. [ABSTRACT FROM AUTHOR]

In this work, chitosan, a biopolymer was cross-linked using glutaraldehyde (Gl) and modified by natural apatite. The Cs-Gl@Fap composite was used to adsorb methyl orange from an aqueous solution. The materials were characterised by SEM-EDX, FTIR, XRD and TGA-DTG analysis confirming the successful synthesis of Cs-Gl@Fap. The effects of experimental variables on adsorption efficiency were examined. Adsorption studies showed that the maximum adsorption capacity was 225.55 mg/g at an equilibration time of 120 min. The pseudo-second-order rate expression supported data best, while the Langmuir equation could satisfactorily describe isotherm data. The thermodynamic constants of the adsorption process were evaluated. The results showed that the stabilisation by contact of methyl orange on Cs-Gl@Fap was endothermic and spontaneous. Additionally, when reused, the hybrid adsorbent remains at approximately 83% of its original capacity after five adsorption cycles. [ABSTRACT FROM AUTHOR]

The removal of methyl tertiary butyl ether (MTBE) from simulated water is going to be a critical environmental issue. The aims of the present study are to synthesise the Fe3O4/SiO2/TiO2 magnetic nanoparticles (MNPs) and evaluate its efficiency for the removal of MTBE by UV/O3/Fe3O4/SiO2/TiO2 combined process (CP) from water. The MNPs were synthesised via modified method and characterised using XRD, SEM and EDS. Then, the effects of initial ozone concentration, pH, MNP concentration, initial MTBE concentration (C0) and irradiation time were evaluated. The findings depicted that the performance of CP is better than separate processes. The optimum condition with initial ozone concentration of 150 mg/L, pH of 8, MNP concentration of 0.1 g/L and C0 of 10 mg/L at 60 min irradiation time results in maximum degradation of MTBE up to 91.65%. Also, the mineralisation rate of MTBE was achieved 68% removal at the same condition. Kinetic profile presented that the reduction of MTBE was fitted into second-order kinetics model for all the runs. The findings illustrate the capabilities of CP as a reliable technology to remove MTBE contained in water. [ABSTRACT FROM AUTHOR]

In this study, monometallic (Ni) and bimetallic (Ni-Ag) nanoparticles were synthesised by a bio reduction approach using Cicer Arietinum leaf extract which is known to contain high amount of phenolic and flavonoid compounds that can serve as nano-bio sources for synthesis metallic NPs. Biosynthesised nanoparticles were characterised using various techniques viz UV-Vis, FE-SEM, EDX, and XRD. The average crystallite diameter was found to be 30 nm and 24 nm for NiNPs and Ni-AgNPs, respectively, with almost spherical shapes, regular morphology and homogenously formed. The synthesised NPs were successfully applied for adsorption of toluidine blue dye (TBO) in aqueous solution using batch experiments with different process parameters namely initial dye concentration, contact time, pH, adsorbent dosage, and temperature. The adsorption isotherms and kinetics were investigated in detailed; the results followed Freundlich model (R2 = 0.990, 0.976) and pseudo-second-order kinetic (R2 = 0.998, 0.999) for both mono and bimetallic NPs, respectively. Finally, adsorption process showed that bimetallic Ag-NiNPs (qe = 94 mg g−1) could be considered more efficient for removal of TBO dye than NiNPs (qe = 87 mg g−1). [ABSTRACT FROM AUTHOR]