Changes In Diffraction Pattern Research Articles

Unveiling Nanogranular Advancements in Nickel-Doped Tungsten Oxide for Superior Electrochromic Performance

Electrochromic materials allow for precise control of their optical properties by applying an electric field, which has led to recent developments in energy-saving and indoor temperature control systems like smart windows. The selective incorporation of metal dopants is an effective technique for generating highly advanced semiconducting metal oxides with precisely customized physicochemical characteristics. In this report, we employed a one-step electrodeposition process to fabricate nickel-doped tungsten oxide (W–Ni) thin films, systematically probing the impact of nickel (Ni) doping on the collective material characteristics. Comprehensive X-ray diffraction research revealed significant changes in diffraction patterns, suggesting slight modifications in the structure caused by Ni doping. The scanning electron microscopy showed complex differences in the microstructure of the film, such as a dense surface, porosity, and clustering of nanogranules. The WNi-3% thin film doped at 3 wt. % exhibited excellent electrochromic performance by efficiently handling lithium ions and displaying favorable electrochromic properties. The improved electrode, WNi-3%, showed a maximum optical modulation of 81.90%, exceptional reversibility of 99.4%, and a high coloration efficiency of 75.12 cm2/C. These findings underscore the efficacy of Ni-doping in tailoring the electrochromic properties of nickel-doped tungsten oxide thin films, thereby advancing the frontiers of high-performance electrochromic materials for energy-efficient applications.

Amorphous-crystalline phase transition and intrinsic magnetic property of nickel organic framework for easy immobilization and recycling of β-Galactosidase

This work describes the synthesis of fibrous nickel-based metal organic framework (Ni-ZIF) via simple solvothermal method. The material formed was calcinated at 400, 600, 800 °C to improve its surface area, porosity and enzyme binding capacity. Changes in X-ray diffraction pattern after calcination revealed the Ni-ZIF transitioned from amorphous to crystalline structure. The surface area, pore volume and pore size for Ni-ZIF@600 were found to be 312.15 m2/g, 0.88 cm3/g and 10.28 nm, with an enzyme loading capacity of 593.85 mg/g after 30 h The free (β-Gal-LEH) and immobilized β-Galactosidase were stable at pH 7.5, temperature 50 °C, and yielded 70.70 and 63.95 mM glucose after milk lactose hydrolysis, respectively. The Ni-ZIF@600@β-Gal-LEH exhibited high enzyme retention capacity, maintaining 59.44 % of its original activity after 6-cycles. The enhanced magnetic property, enzyme binding capacity and easy recoverability of the calcinated Ni-ZIF could guarantee its industrial significance as immobilization module for enzyme-mediated catalysis.

CATALYTIC CRACKING OF CRUDE PALM OIL USING Cr/PALM SHELL CHARCOAL IMPREGNATION CATALYST

The study of synthesizing Cr/activated palm shell charcoal catalyst by impregnation method has been done. Cr/Activated Charcoal was made using variation of chromium concentration (1%, 2% and 3%). Change in diffraction pattern in XRD analysis for charcoal before modification and after modification showed chromium has been successfully impregnated to the catalyst. The higher the chromium compound concentration used, the greater %-weight of chromium in the catalyst. It was found that the use of Cr-2%/Charcoal catalyst was able to increase the percentage of cracking liquid yield at the temperature of 550oC as much as 62,44% compared to the percentage of liquid yield from thermal cracking was 60,1% at the same temperature. It was also observed, using the Cr/Charcoal catalyst from impregnation method is more effective than catalyst from ion exchange method. However, the density of the cracking liquid yield is not yet close to the standard density range for fuel.

Scattering of Attosecond Laser Pulses on a DNA Molecule during Its Nicking and Bending

It is well known that X-ray crystallography is based on X-ray diffraction (XRD) for atoms and molecules. The diffraction pattern arises as a result of scattering of incident radiation, which makes it possible to determine the structure of the scattering substance. With the advent of ultrashort radiation sources, the theory and interpretation of X-ray diffraction analysis have remained the same. This work shows that when an attosecond laser pulse is scattered on a DNA molecule, including during its nicking and bending, the pulse duration is an important characteristic of the scattering. In this case, the diffraction pattern changes significantly compared to the previously known scattering theory. The results obtained must be used in XRD theory to study DNA structures, their mutations and damage, since the previously known theory can produce large errors and, therefore, the DNA structure can be “decoding” incorrectly.

Lattice strain visualization inside a 400 nm single grain of BaTiO3 in polycrystalline ceramics by Bragg coherent X-ray diffraction imaging

The degree of anisotropy and the domain arrangement of crystal structures in ferroelectrics are affected by the grain boundaries and by the shape and size of the grains. To understand the grain boundary effects that occur in ferroelectric ceramics, we introduce a technique for nondestructively observing the internal lattice strain distribution of a submicrometer-sized ferroelectric grain in polycrystalline materials. The ferroelectric phase transition of a single grain in the polycrystalline materials was evaluated by tracking the changes in the Bragg coherent X-ray diffraction (CXD) patterns. The internal lattice strain distribution of the grains in the paraelectric phase was visualized via Bragg CXD imaging. A pair of 90° domains in the ferroelectric phase were also imaged in three dimensions, and showed a domain boundary correlated with the internal lattice strain caused by the stresses from the adjacent grains.

In Situ Synchrotron X-ray Scattering Investigation of Cathodic ZIF-8 Deposition on Graphite Using 3D-Printed Cells

Electrochemical approaches provide unique means to fabricate thin films of metal-organic frameworks (MOFs). However, the kinetics of electrochemical MOF deposition has not been quantitatively investigated so far. In this study, we report the first in situ measurements of electrochemical MOF growth using transmission synchrotron X-ray scattering. Electrochemical cells based on poly(lactic acid) with two windows were fabricated using fused-deposition modeling. The resulting three-dimensional (3D)-printed cells, the surface of which was coated with paraffin wax to prevent solvent percolation through the polymer material, were used to monitor the cathodic growth of zeolitic imidazolate framework-8 (ZIF-8) on graphite in a methanol solution containing ZnCl2 and 2-methylimidazole (Hmim) at different cathodic potentials. The resulting time-resolved X-ray diffraction data showed a gradual increase in crystal size with negligible changes in crystal orientation during the cathodic ZIF-8 deposition. More importantly, the time-resolved data provided a means to quantitatively assess the kinetics of the cathodic ZIF-8 growth using the Gualtieri model, revealing that the cathodic potential and Hmim concentration affected crystal growth kinetics but not nucleation kinetics. These ZIF-8 samples exhibited changes in X-ray diffraction patterns after being washed with methanol and dried in air, indicating that in situ measurements are essential to investigate mechanisms behind MOF electrodeposition.

Crystal structure, vibrational and chemical properties and phase transitions in Glycyl-DL-Aspartic acid and Glycyl-DL-Aspartic acid monohydrated.

In this paper, the structural and vibrational analysis of the dipeptides glycyl-DL- aspartic acid hydrate (H-Gly-DL-Asp-OH.H2O) crystal, with P1¯ (C11) triclinic symmetry and glycyl-DL- aspartic acid (H-Gly-DL-Asp-OH) crystal, with Cc space group (Cs4) monoclinic structure, were studied. The crystallographic structures of these molecules were determined by single-crystal X-ray diffraction. Changes in the powder X-ray diffraction patterns of H-Gly-DL-Asp-OH.H2O as a function of the temperature were recorded. After 403 K, the water molecule detaches itself from H-Gly-DL-Asp-OH.H2O, causing its symmetry to change from triclinic to monoclinic. The normal modes of vibration were analyzed through calculations based on Density Functional Theory (DFT) using the B3LYP functional with the Gaussian bases 6–311++G (d,p) and potential energy distribution (PED) analysis. These results, together with literature data and Raman and infrared (IR) spectroscopy measurements, allowed the identification of the various vibrational normal modes. Furthermore, the effect of high pressure on H-Gly-DL-Asp-OH.H2O was studied by Raman spectroscopy experiments. The results obtained from the Raman spectra at high pressures indicate changes around 2.1 and 4.5 GPa, such as the disappearance, splitting and emergence of some modes, as well as discontinuities in the evolution of wavenumbers of several normal modes of vibration. Such changes involved modes localized in the region of external modes, while others involved molecular backbone modes and modes that participate in hydrogen bonding. The changes were related to small conformational changes associated with H bonds and small deformations in hydrated dipeptide molecules.

Search for octupolar order in NpO2 by neutron powder diffraction

The magnetic structure of neptunium dioxide (NpO2) remains a mystery despite decades of research. We revisited the search for magnetic ordering in NpO2 by performing a powder neutron diffraction experiment at low temperatures and relatively large values of Q. Diffraction data were collected for 300 ​mK, 15 ​K, and 35 ​K to understand the phase transition near 25 ​K. However, no significant changes in the neutron diffraction pattern were identified. Using the octupolar magnetic form factor j6, the maximum theoretical expected value of the magnetic moment (3.27 μB), the calculated magnetic Bragg peak intensities would not be observable in neutron powder diffraction data. This value is much larger than the previously estimated magnetic moment of ∼0.1 μB. Supported by experimental results, these calculations suggest that unpolarized neutron powder diffraction is unsuitable for measuring octupolar ordering in NpO2.

Peculiarities of Scattering of Ultrashort Laser Pulses on DNA and RNA Trinucleotides

Currently, X-ray diffraction analysis (XRD) with high spatial and time resolution (TR-XRD) is based on the known theory of X-ray scattering, where the main parameter of USP-its duration-is not taken into account. In the present work, it is shown that, for scattering of attosecond USPs on DNA and RNA trinucleotides, the pulse length is the most important scattering parameter. The diffraction pattern changes considerably in comparison with the previously known scattering theory. The obtained results are extremely important in TR-XRD when using attosecond pulses to study trinucleotides of DNA and RNA, because with the previously known scattering theory, which does not take into account the duration of USP, one cannot correctly interpret, and therefore "decode", DNA and RNA structures.

Study of solid state transformations and their effect on mechanical response in the stoichiometric Ni2Cr using in-situ synchrotron radiation diffraction experiments

A complete microstructural characterization of the stoichiometric Ni2Cr alloy after different ageing times in which different degrees of order are attained has been carried out. The study of order-disorder transformation has been done using synchrotron radiation diffraction monitoring eventual changes in high-energy X-ray diffraction (HEXRD) patterns every six seconds in the course of differential scanning calorimetry DSC experiments. According to acquired data, the onset of the order-disorder transformation occurs at 630 °C, temperature higher than that reported in previous works. In addition, the appearance of fine carbide precipitation has also been found inside the grains and at grain boundaries. Both ordering of the stoichiometric Ni2Cr and carbide precipitation seems to be responsible for the strengthening of the alloy.

Tailoring the properties of chitosan by grafting with 2-mercaptobenzoic acid to improve mucoadhesion: in silico studies, synthesis and characterization.

Mucoadhesive polymers improve oral bioavailability of drugs by prolonging the duration of adhesion of drugs with mucosa. Various methods could be employed to address the problems of mucoadhesive polymers like weak adhesion forces. Chemical modification of polymers, such as the addition of a thiol group or thiolation, is another way for improving the polymers' mucoadhesive properties that is studied in present research work. A novel thiomer of chitosan was prepared by attaching 2-mercaptobenzoic acid, a hydrophobic ligand onto it. The docking of thiomer and chitosan with mucin structure showed higher binding energy for former. The prepared thiomer was subjected to X-ray diffraction and DSC which established reduction in crystallinity and formation of a new compound through changes in glass transition, melting point and change in diffraction pattern. The NMR studies established conjugation of 2-mercapto benzoic acid to chitosan. The increased mucoadhesion in thiomer behaviour (2-3fold) was confirmed through mucus glycoprotein assay as well as through texture analysis. The permeation enhancing the property of thiomer was established by demonstrating the permeation of phenol red across thiomer treated intestinal membrane. An in vitro cell toxicity assay was done to establish toxicity of chitosan and thiolated chitosan. Finally, the reduced water uptake of thiomer over chitosan proved that the increase in mucoadhesion is not contributed by swelling. Thus, a thiomer with improved mucoadhesion and enhanced permeation properties was prepared and characterized. Hence, all these properties render the newly synthesized polymer a better alternative to chitosan as an excipient for mucoadhesive drug delivery systems.

Laser Written Stretchable Diffractive Optic Elements in Liquid Crystal Gels

Direct laser writing (DLW) in liquid crystals (LCs) enables a range of new stimuli-responsive functionality to be realized. Here, a method of fabricating mechanically tunable diffraction gratings in stretchable LC gels is demonstrated using a combination of two-photon polymerization direct laser writing (TPP-DLW) and ultraviolet (UV) irradiation. Results are presented that demonstrate the fabrication of a diffraction grating that is written using TPP-DLW in the presence of an electric field in order to align and lock-in the LC director in a homeotropic configuration. The electric field is subsequently removed and the surrounding regions of the LC layer are then exposed to UV light to freeze-in a different alignment so as to ensure that there is a phase difference between the laser written and UV illuminated polymerized regions. It is found that there is a change in the period of the diffraction grating when observed on a polarizing optical microscope as well as a change in the far-field diffraction pattern when the film is stretched or contracted. These experimental results are then compared with the results from simulations. The paper concludes with a demonstration of tuning of the far-field diffraction pattern of a 2-dimensional diffraction grating.

Signatures of Majorana bound states and parity effects in two-dimensional chiral p -wave Josephson junctions

We characterize topological features of Josephson junctions formed by coupled mesoscopic chiral $p$-wave superconducting islands. Through analytic and numerical studies of the low-lying BdG (Bogoliubov-de Gennes) spectrum, we identify localized MBS (Majorana bound states) nucleated in Josephson vortices by the application of a perpendicular magnetic field. Additionally, we demonstrate the existence of an extended MBS that is delocalized around the outer perimeter of the coupled islands, which has measurable consequences on the Josephson supercurrent and phase dynamics of the junction. In particular, we predict a change in the critical current diffraction pattern in which the odd integer-flux nodes are lifted in a fermion parity-dependent fashion. We model the competing stochastic effects of thermal noise and macroscopic quantum tunneling within the RCSJ framework and show the emergence of a bimodal critical current distribution. We demonstrate that increasing the parity transition rate suppresses the bimodal nature of the distribution, thus strongly emphasizing the non-trivial parity dependent nature of the many-body ground state. Finally, we consider a trijunction geometry with three islands and discuss possible schemes to braid Majorana bound states by moving the Josephson vortices to which they are bound.

Ultrasensitive Molecular Detection at Subpicomolar Concentrations by the Diffraction Pattern Imaging with Plasmonic Metasurfaces and Convex Holographic Gratings

Compact and cost‐effective optical devices for highly sensitive detection of trace molecules are significant in many applications, including healthcare, pollutant monitoring and explosive detection. Nanophotonic metasurface‐based sensors have been intensively attracting attentions for molecular detection. However, conventional methods often involve spectroscopic characterizations that require bulky, expensive and sophisticated spectrometers. Here, a novel ultrasensitive sensor of plasmonic metasurfaces is designed and fabricated for the detection of trace molecules. The sensor features a convex holographic grating, of which the first‐order diffraction pattern of a disposable metasurface is recorded by a monochrome camera.The diffraction pattern changes with the molecules attached to the metasurface, realizing label‐free and spectrometer‐free molecular detection by imaging and analyzing of the diffraction pattern. By integrating the sensor with a microfluidic setup, the quantitative characterization of rabbit anti‐human Immunoglobulin G (IgG) and human IgG biomolecular interactions is demonstrated with an excellent limit of detection (LOD) of 0.6 pm. Moreover, both the metasurface and holographic grating are obtained through vacuum‐free solution‐processed fabrications, minimizing the manufacturing cost of the sensor. A prototype of the imaging‐based sensor, consisting of a white light‐emitting diode (LED) and a consumer‐level imaging sensor is achieved to demonstrate the potential for on‐site detection.

Simultaneous imaging and diffraction in the dynamic diamond anvil cell.

The ability to visualize a sample undergoing a pressure-induced phase transition allows for the determination of kinetic parameters, such as the nucleation and growth rates of the high-pressure phase. For samples that are opaque to visible light (such as metallic systems), it is necessary to rely on x-ray imaging methods for sample visualization. Here, we present an experimental platform developed at beamline P02.2 at the PETRA III synchrotron radiation source, which is capable of performing simultaneous x-ray imaging and diffraction of samples that are dynamically compressed in piezo-driven diamond anvil cells. This setup utilizes a partially coherent monochromatic x-ray beam to perform lensless phase contrast imaging, which can be carried out using either a parallel- or focused-beam configuration. The capabilities of this platform are illustrated by experiments on dynamically compressed Ga and Ar. Melting and solidification were identified based on the observation of solid/liquid phase boundaries in the x-ray images and corresponding changes in the x-ray diffraction patterns collected during the transition, with significant edge enhancement observed in the x-ray images collected using the focused-beam. These results highlight the suitability of this technique for a variety of purposes, including melt curve determination.

Preparation and characterization of fluorine-substituted LiFeBO3 with carbon coating to enhance electrochemical performance and stability as a cathode material for Li-ion batteries

The fluorine-substituted LiFeBO3 with carbon coating (LFeBF/C) has been successfully demonstrated via a solid-state reaction to enhance its electrochemical properties and stability in air. Transmission electron microscopy characterization reveals that the primary LFeBF particles are fully covered by a thin layer of amorphous carbon. The formation of vonsenite-type LFeBF/C and the distribution of Li ions into its octahedral sites due to the fluorine substitution are confirmed using X-ray diffraction and solid-state nuclear magnetic resonance measurements, respectively. The stability of the LFeBF/C in air is promoted by the carbon layer. After two months of open-air storage, no significant changes in X-ray diffraction patterns can be observed. The synergistic effects of fluorine substitution and carbon coating enhance the overall electrochemical performance of the LFeBF/C as achieving a superior initial discharge capacity of 367.0 mAh g−1 at the rate of 0.05C and 231.7 mAh g−1 at 1.0C. In addition, the cyclic stability of the LFeBF/C is improved, reaching 197.5 mAh g−1 at the rate of 1.0C after 50 cycles, which corresponds to a retention of 85% of its initial capacity.

Strain-induced changes of the X-ray diffraction patterns of cross-linked Poly(dimethylsiloxane): The texture hypothesis

Poly(dimethylsiloxane) is a widely used silicone polymer that undergoes partial crystallization both as free oil and rubber when sufficiently cooled. However, a description of its crystalline structure surprisingly remains a totally open question. In particular X-ray diffraction fiber patterns of stretched silicone rubbers display impressive changes with strain and a recently proposed explanation involves a rich polymorphism. The present study develops the different idea that the X-ray pattern evolution merely reflects changes in the crystalline texture: a single crystalline phase is present with a structure virtually unaffected by strain while the axis of preferential orientation for the crystallites progressively changes. This enables a quantitative description of the X-ray fiber patterns, but the remaining fundamental structural issues are underlined. • The structure of the crystalline phase of polydimethylsiloxane remains an open question. • A simple explanation for the evolution of low-temperature x-ray patterns is proposed. • It includes a single crystalline phase and changes in crystalline texture. • A fundamental issue is the orientation of polymer chains in the crystal unit cell.

Aumento na capacidade de troca de cátions em rochas biotitas ricas em Mg ou Fe pela ação da rizosfera do milho

ABSTRACT The weathering of some silicate minerals in crushed rocks may occur in a few days of cropping and generate different physicochemical properties, with potential benefits to tropical soils. This study aimed to investigate the infuence of maize (Zea mays L.) rhizosphere on the weathering products and on the cation exchange capacity of Mg-biotite from biotite schist and Fe-biotite from biotite syenite. An experiment was carried out in pots, so that plants and crushed rock materials could be evaluated during seven successive growth cycles. The nutrients iron and potassium were taken up from biotite schist and biotite syenite during cropping. The weathering of both biotites promoted by the rhizosphere caused mineralogical changes. The most expressive change in the X-ray diffraction patterns occurred in the < 53 µm particle size fraction; however, the 53-300 µm fractions also changed. The alteration in the Mg-biotite, which has a lower Fe/Mg relation in octahedral sites than the Fe-biotite, was responsible for the most expressive cation exchange capacity increase in the fractions < 300 µm. However, the Fe-biotite weathering process, which presents a higher Fe/Mg relation in octahedral sites, did not increase the cation exchange capacity.

In Situ Transmission Electron Microscopy Analysis of Microstructure Evolution of the Li6PS5cl Solid Electrolyte in Charge/Discharge Process

All solid state lithium battery has been attracting attention for its high energy density and safety compared to current lithium ion battery. Here, sulfide-based solid electrolytes (SEs) such as Li6PS5Cl have extremely high lithium ion conductivity, which make them promising candidate for the application. However, their stability against lithium metal anode is under debate. And how does the SE reacts with the Li metal in contact and its effect on the performance is not well understood.In this work, we conducted in situ transmission electron microscopy (TEM) experiments to directly observe the structural changes of Li6PS5Cl (LPSCl) solid electrolyte in contact with lithium metal under bias to clarify its stability against lithium. After contacting them under -1 V of biasing on LPSCl with respect to the lithium metal, the surface of the LPSCl shrunk. Electron diffraction pattern analysis revealed that the initial crystalline structure was lost and LPSCl was amorphized upon contact with lithium. The reaction propagated ~1.5 mm after 4 minutes of biasing, and the structural change was irreversible. In addition, lithium transport through the SE/SE boundary was observed to study the degradation due to the Li concentration gradient at the grain boundaries caused by the slower Li diffusion across the boundaries. When a bias potential was applied across the SE/SE interface between two LPSCl particles, a change in the contrast at the interface was observed. After the two particles were detached, the particle slowly recovered the original contrast. The result indicates there was a shift of Li ions within the particle away from the SE/SE interface due to the driving force from the applied bias. To investigate the structural evolution in the grain boundaries under charge/discharge process, alternating bias potential was applied between the LPSCl particles. The change in the electron diffraction pattern during the alternating bias experiment showed emerging peaks for Li2S, which implies the repeating shift of Li ions within the LPSCl altered the electrolyte structure that may degrade the performance of the SE.Observations in this work revealed that the degradations of the SE may take place at the grain boundaries in addition to the electrochemical interface with lithium metal. The structural change at the grain boundaries may cause reduced ionic conductivity and/or increased electrical conductance which may lead to lithium precipitation inside the SEs that can cause catastrophic failure of the battery due to shorting. Figure caption : In situ TEM observation of lithium shift at SE/SE interface in Li6PS5Cl solid electrolyte under alternating bias potential between -3 and +3 V. Figure 1

Highly phosphorescent dinuclear Cu(I) complexes with iminephosphine tetradentate chelating ligand (PNNP): Structures and luminescence properties

Two dinuclear copper(I) iodide complexes [Cu(μ-I)]2L (1) and [CuIPPh3]2L (2), based on a new iminephosphine tetradentate chelating ligand (PNNP), have been synthesized and characterized. The crystal structures of the complexes display distorted tetrahedron configurations around Cu(I) centers. In powder at 298 K, these complexes exhibit bright orange-red and yellow emissions with excellent photo-luminescent quantum yields of 54.6% (1) and 66.8% (2), and short lifetimes of 2.26 μs (1) and 2.32 μs (2), respectively. The reversible mechanochromic luminescent (MCL) properties of complex 2 have been confirmed by monitoring the changes in emission spectra and X-ray diffraction patterns. X-ray crystallography analysis reveals that the unique pore structure filled with CHCl3 molecule is considered to be the origin of MCL properties of 2.