Diffraction Pattern Images Research Articles

Titanium surface functionalization via directed energy deposition of CuNiTi ternary alloy

Pure titanium is a soft material that tends to degrade quickly during service due to wear and microbiologically influenced corrosion. Therefore, current research aims at the deposition, microstructural characterization, and surface functionalization of the TiCuNi coatings on pure titanium substrate to improve its surface properties. Cu–Ni premixed elemental powders are deposited on the pure Ti by laser-directed energy deposition (LDED) using a novel method of extracting Ti from the substrate through melt pool convection. The single-track deposit geometry and integrity characterization using dilution percentage, heat-affected zone width (HAZ), and microhardness values show the sound metallurgical bonding with the substrate. The X-ray diffraction (XRD) pattern and microstructure image reveal the presence of NiTi binary (B2) and Ti2CuNi ternary (B19) hard phases and equiaxed dendritic morphology, respectively, demonstrating ternary alloy coating formation. The microhardness value of the coatings is thrice that of the substrate due to the presence of hard NiTi (B2) binary and Ti2CuNi (B19) ternary phases. The coating’s wear resistance is significantly (80%) higher than the substrate, owing to hard phases and Cu as a solid lubricant. The wear track consists of small grooves, adhered debris, and a smooth profile, mainly due to a significant reduction in adhesion and abrasion compared to the substrate. Moreover, the polarisation corrosion potential and current density are increased and decreased by 53% and 97%, respectively, displaying symbolic improvement in the corrosion resistance. Hence, this work has presented the LDED ability to enhance the pure Ti anti-wear and corrosion resistance properties by depositing CuNiTi ternary alloy coating for potential aerospace, marine, and biomedical applications.

DENNIS: a design and analysis tool for dynamic material x-ray diffraction experiments

We present DENNIS (Diffraction Experiment desigN and aNalysiS): a graphical software tool useful for the design and analysis of dynamic x-ray diffraction experiments, such as those performed on the Z Pulsed Power Facility, Thor Pulsed Power Generator, and Dynamic Compression Sector (DCS) of the Advanced Photon Source. DENNIS provides rapid powder and single-crystal diffraction pattern predictions and powder diffraction pattern image integration in three-dimensional geometries. Additional features include crystallographic information file reading, image processing, and synthetic diffraction pattern image generation. We overview the software's capabilities, detail the prediction and integration methodologies, and provide example implementations on Z and DCS experiments.

Fully automated analysis approach for in situ electron diffraction

Despite the rapid development of the state-of-the-art in-situ/operando transmission electron microscopy technologies capable of generating a substantial volume of diffraction pattern images in a compressed time frame, the associated image interpretation apparatus remains incompletely automated. Since the analysis of the acquired data is predominantly focused on a subset of this extensive data set, there is the potential for critical information to be inadvertently omitted. Using a set of computer vision algorithms, we have developed a fully automated computational tool specifically tailored for the systematic analysis of electron diffraction patterns. Our research results demonstrate that the proposed methodology represents a viable and effective approach for the automated analysis of the substantial corpus of data collected during in-situ experimental investigations.

Agro-waste mediated silver nanoparticles from Pithecellobium dulce (Roxb.) Benth fruit peel and their multifaceted biomedical applications

The present work aimed to produce silver nanoparticles using an agro-waste fruit peel extract from Pithecellobium dulce (Roxb.) Benth (PD) and examine their antibacterial, antioxidant, and anticancer characteristics. The synthesized silver nanoparticles (PD-AgNPs) were validated by the characteristic dark brown hue and surface plasmon resonance at 417 nm. Fourier transform infra-red spectrum pinpoints the important functional groups in charge of their reduction and capping. The X-ray diffraction pattern and transmission electron microscopic images confirmed the face-centred cubic crystal structure and spherical-shaped PD-AgNPs. Particle size and stability of the PD-AgNPs were found to be 83.90 and −31.2 mV respectively. Antibacterial experiments against E. coli, K. pneumoniae, B. subtilis, and S. aureus showed concentration-dependent inhibitory effects. In various assays, including those for DPPH, hydroxyl, superoxide anions, and ABT radicals, PD-AgNPs exhibited strong free radical scavenging abilities when compared with vitamin C. In the MTT experiment, PD-AgNPs displayed dose-dependent cytotoxicity against MG-63 cells with an IC50 of 22.09 µg/mL. Additionally, the anticancer potential of PD-AgNPs was studied by measuring mitochondrial membrane potential and apoptosis. The potential of PD-AgNPs for utilization in biomedical applications was established by their antibacterial, antioxidant, and anticancer characteristics. The study emphasizes the importance of green synthesis methodologies in creating multifunctional nanoparticles with therapeutic potential, which warrants further investigation for practical medical applications.

Bragg Spot Finder (BSF): a new machine-learning-aided approach to deal with spot finding for rapidly filtering diffraction pattern images

Macromolecular crystallography contributes significantly to understanding diseases and, more importantly, how to treat them by providing atomic resolution 3D structures of proteins. This is achieved by collecting X-ray diffraction images of protein crystals from important biological pathways. Spotfinders are used to detect the presence of crystals with usable data, and the spots from such crystals are the primary data used to solve the relevant structures. Having fast and accurate spot finding is essential, but recent advances in synchrotron beamlines used to generate X-ray diffraction images have brought us to the limits of what the best existing spotfinders can do. This bottleneck must be removed so spotfinder software can keep pace with the X-ray beamline hardware improvements and be able to see the weak or diffuse spots required to solve the most challenging problems encountered when working with diffraction images. In this paper, we first present Bragg Spot Detection (BSD), a large benchmark Bragg spot image dataset that contains 304 images with more than 66 000 spots. We then discuss the open source extensible U-Net-based spotfinder Bragg Spot Finder (BSF), with image pre-processing, a U-Net segmentation backbone, and post-processing that includes artifact removal and watershed segmentation. Finally, we perform experiments on the BSD benchmark and obtain results that are (in terms of accuracy) comparable to or better than those obtained with two popular spotfinder software packages (Dozor and DIALS), demonstrating that this is an appropriate framework to support future extensions and improvements.

Synthesis and characterization of gold/nickel oxide nanoalloy via green laser irradiation

In the present study, a gold/nickel oxide (Au/NiO) nanoalloy was generated by irradiating two nano-metallic material solutions using a green laser. The produced Au/NiO nanocomposites were characterized by UV–Vis–NIR spectroscopy, an X-ray diffraction pattern, TEM and SEM imaging, and photoluminescence and DLS tests. Depending on the concentration of Au NPs in the suspension medium, the final characteristics of Au/NiO nanocomposites vary significantly. Au NPs exhibit an extremely high plasmonic absorption peak at approximately 530 nm. They melted by absorbing the energy of the second harmonic of the laser beam, forming an Au/NiO nanocomposite. Additionally, our results demonstrated that after irradiation with a green laser, the bandgap energy of samples was reduced to 5, 4.3, and 4 eV as the number of Au NPs in nanocomposite structures increased, indicating that the addition of gold to nickel oxide NPs improves their conductivity and reduces the bandgap energy of samples. Moreover, due to composition formation, the number and size of Au NPs dropped following green laser irradiation, while NiO NPs grew in size. This work created an AuNiO nanocomposite by laser ablation, which is a highly effective approach for fabricating nanostructures.

Feature extraction and spatial imaging of synchrotron radiation X-ray diffraction patterns using unsupervised machine learning

Feature extraction and spatial imaging of synchrotron radiation X-ray diffraction patterns using unsupervised machine learning

High Thermoelectric Performance in 2D Sb2Te3 and Bi2Te3 Nanoplate Composites Enabled by Energy Carrier Filtering and Low Thermal Conductivity.

Thermoelectrics are an important class of materials with great potential in alternative energy applications. In this study, two-dimensional (2D) nanoplates of the layered chalcogenides, Sb2Te3 and Bi2Te3, are synthesized and composites of the two are investigated for their thermoelectric properties. The two materials, Sb2Te3 and Bi2Te3, were synthesized as hexagonal, 2D nanoplates via a colloidal polyol route. The as-synthesized Sb2Te3 and Bi2Te3 vary drastically from one another in their lateral and vertical dimensions as revealed by scanning electron microscopy and atomic force microscopy. The single crystalline nanoplate nature is deduced by high-resolution transmission electron microscopy and selected area electron diffraction. Nanoplates have well-defined hexagonal facets as seen in the scanning and transmission electron microscopy images. The nanoplates were consolidated as an anisotropic nanostructured pellet via spark plasma sintering. Preferred orientation observed in the powder X-ray diffraction pattern and scanning electron microscopy images of the fractured pellets confirm the anisotropic structure of the nanoplates. Thermoelectric properties in the parallel and perpendicular directions were measured, revealing strong anisotropy with a significant reduction to thermal conductivity in the perpendicular direction due to increased phonon scattering at nanoplate interfaces. All compositions, except that of the 25% Bi2Te3 nanoplate composite, behave as degenerate semiconductors with increasing electrical resistivity as the temperature increases. The Seebeck coefficient is also increased dramatically in the nanocomposites, the highest reaching 210 μV/K for 15% Bi2Te3. The increase in Seebeck is attributed to energy carrier filtering at the nanoplate interfaces. Overall, these enhanced thermoelectric properties lead to a drastic increase in the thermoelectric performance in the perpendicular direction, with zT ∼ 1.26, for the 15% Bi2Te3 nanoplate composite at 450 K.

Micro- to nanoscale constraints on metasomatic alterations of xenotime, inclusions of Th-, U- and Pb-phases and their geochronological implications (Ås pegmatite, Evje and Hornnes, S Norway)

Five crystals of pegmatitic xenotime from Ås II feldspar quarry (Evje, S Norway) were studied with comprehensive analytical methods from microscale to nanoscale with respect to fluid-mediated alterations and their geochronological implications. Xenotime crystals are strongly altered during dissolution-reprecipitation processes that resulted in the formation of (Th, U)-depleted xenotime subdomains with numerous microinclusions of (Th, U)-silicate, uraninite and minor galena. Remains of a primary xenotime (Xtm1) yielded LA-ICPMS UPb data characterized by a reverse discordance (from −10.5 to −2.6%) with a 208Pb/232Th mean age 988.4 ± 5.9 Ma (95% conf., MSWD = 0.75, n = 71), which is within uncertainty with a 207Pb/235U mean age 979.1 ± 5.0 Ma (95% conf., MSWD = 1.4, n = 22) yielded by data filtered to below ±5% discordance (i.e., from −5.0 to −2.6%). The altered xenotime domains (Xtm2) provided highly scattered dates, including 208Pb/232Th dates from 200 ± 14 to 2135 ± 120 Ma (n = 135). Discordant UPb data yielded upper intercept age 909 ± 16 Ma (MSWD = 7.9). EPMA Th-U-total Pb measurements and compositional characteristics of uraninite inclusions indicate three age populations of ca. 852–983, 594–687 and 37–101 Ma.TEM investigations revealed initial alterations within domains Xtm1, representing a primary xenotime, which progressed along parallel submicron- to nanoscale fractures. These fractures represent partially open grain boundaries, which are empty or are filled with secondary inclusions of (Th, U)-silicates, uraninite or coffinite. The submicron-sized inclusions are accompanied by subdomains of (Th, U)-depleted xenotime. Altered xenotime (Xtm2) is well crystalline in TEM imaging and electron diffraction patterns in contrast to primary unaltered xenotime domains (Xtm1) that demonstrate, in Raman spectra, moderate degree of radiation damage caused by U and Th decay. Secondary inclusions of Th and U phases are nanocrystalline or amorphous, which increases their potential for Pb-loss or accumulation of Pb in excess. Some of them contain nanoinclusions of Pb3O4 or metallic Pb, whereas <100 nm-sized inclusions of (Pb, Sb)-oxide formed in the altered xenotime.To summarize, this study provides important insights for our understanding of coupled dissolution-reprecipitation processes that affect xenotime and mobilization of released U, Th and Pb. Removal of highly mobile U in a fluid, and the presence of nanoinclusions of Pb3O4, (Pb, Sb)-oxide and metallic Pb have particular importance for xenotime dating and explain disturbance towards older ages. Nevertheless, both removal of U, Th and Pb from altered and recrystallized xenotime as well as presence of submicron- to nanoinclusions can result in age disturbance resulting in spread of dates along a concordia curve.

Effect of goethite (α-FeOOH) nanoparticles on the surface properties and flotation behavior of chalcopyrite

Chalcopyrite flotation is selectively depressed by oxidation treatment. The presence of ferric oxyhydroxide on the surface of chalcopyrite after oxidation treatment is a key factor in depressing chalcopyrite flotation. However, there is no concrete evidence that ferric oxyhydroxide has a depressing effect. In addition, the effectiveness of this depressing effect could be enhanced by directly applying ferric oxyhydroxide nanoparticles. This study investigated the effect of goethite (α-FeOOH) nanoparticles on the surface properties and flotation behavior of chalcopyrite. α-FeOOH nanoparticles were produced through chemical precipitation followed by hydrothermal treatment. The crystalline structure of irregular rice grain-shaped α-FeOOH nanoparticles was confirmed by the X-ray diffraction pattern and scanning electron microscope image. Micro-flotation experiments showed that chalcopyrite recovery decreased significantly from 93 % to 13 % when 30 mg/L α-FeOOH nanoparticles was used. This flotation result demonstrated the potential of α-FeOOH nanoparticles as a nanodepressant for the flotation of chalcopyrite. These nanoparticles physically adsorbed on the chalcopyrite surface and rendered its surface hydrophilic, thereby reducing the chalcopyrite flotation recovery. The attractive electrostatic force between the positively charged α-FeOOH nanoparticles and the negatively charged chalcopyrite surface is likely responsible for the adsorption of α-FeOOH nanoparticles on chalcopyrite.

Rapid discrimination of Candida species based on optical diffraction pattern.

Candidiasis occurs mainly in immunocompromised patients. Rapid detection of Candida species can play a major role in the successful management of fungal infections and treatment monitoring. Detection and discrimination of five common strains of Candida species was performed using the optical elastic scattering diffraction pattern of their colonies. Using laser light with 632 nm wavelength and the designed optical system, optical diffraction patterns of C. albicans (ATCC12261), C. tropicalis (ATCC20336), C. glabrata (15545), C. guilliermondii (20216), and C. parapsilosis (22019) were recorded, processed and analyzed. The results of our study show that based on the different structure of Candida species and dissimilar structure of their colonies, the difference between acquired diffraction patterns are recognizable. In addition, through extraction of statistical feature of the diffraction pattern images and using classification techniques, the detection and discrimination could be performed in a semi-automatic way. The analysis of the colonies of five different Candida species by the optical diffraction patterns generated from the interaction of the laser with colonies' structures demonstrated that the technique had the potential to be applied for the detection and discrimination of various species.

Analyzing Properties of Monolayer MoS2 Using RHEED and Ultrafast Electron Diffraction

Reflection high-energy electron diffraction (RHEED) and ultrafast electron diffraction (UED) are techniques used to characterize crystal structures both statically and dynamically. These experimental methods are of academic interest due to their ability to visualize crystal structures on the atomic level and analyze dynamic changes on the picosecond scale. In this experiment, RHEED and UED are implemented to analyze monolayer molybdenum disulfide (MoS2), a compound that may contribute to the future of microelectronics. Images of various diffraction patterns are presented, and analysis is conducted on diffraction peaks, lattice spacing, and photoinduced intensity changes.

2H-MoS 2 Modified Nitrogen-Doped Hollow Mesoporous Carbon Spheres as the Efficient Catalytic Cathode Catalyst for Aprotic Lithium-Oxygen Batteries

2H-MoS ₂ Modified Nitrogen-Doped Hollow Mesoporous Carbon Spheres as the Efficient Catalytic Cathode Catalyst for Aprotic Lithium-Oxygen Batteries

Prediction of Lattice Volumes of Crystal Samples by Computer Image Recognition on the X-ray Diffraction Patterns

Computer image recognition (CIR) on the diffraction patterns of X-ray single crystal diffractometer was used to assist the analysis of the unit cell parameters in terms of lattice volume. This method can improve the prediction accuracy of unit cell parameters in the pre-experiment step since erroneous prediction by the software may occur for 5% tested crystal samples, which may critically affect the complete crystal data quality and cause unnecessary testing time. In the imaging processing, the diffraction pattern images saved as .img format files were firstly batch transferred into .jpg format with high quality for further treatment. Specific features of the crystal diffraction points or zones in the images were extracted for the recognition processing by color mode. The Findcontour algorithm and the Canny algorithm based on Gaussian filtering were used for the diffraction peak points and area detection. The relationship between the distribution of crystal diffraction points (DCDP) and the lattice volumes based on reciprocal lattice theory was established for the users to judge the reasonable location range of the lattice volumes. A Density model was proposed to correlate the dependence of the DCDP and the experimental data. Special crystal samples were chosen to test the CIR performance, and its accuracy for the lattice volume prediction was evaluated. The CIR method can be used for the assistance in the analysis of the lattice volume location range and for crystal structure solving.

Sn2Pd: a possible superconducting material with topological surface states

In this article, we report the detailed magneto transport measurements of topological semimetal candidate, Sn2Pd. Single crystal of Sn2Pd is synthesized through self-flux method. Phase purity and crystalline morphology are confirmed through powder x-ray diffraction pattern and field emission scanning electron microscopy image. Signatures of superconducting transition are seen in both transport and magneto transport measurements, which are further supported by the AC magnetization studies. Sn2Pd is found to show superconductivity onset at below 2.8 K, but not the zero resistivity down to 2 K. Although, isothermal magneto resistivity measurements below superconducting onset (2.8 K) clearly exhibited superconductor like behavior, but is not observed in heat capacity measurements, indicating the same to be of weak nature. Magneto transport measurements performed in normal state of Sn2Pd show the presence of weak antilocalization effect, which is confirmed by modelling of low field magneto-conductivity through Hikami Larkin Nagaoka formalism. Here, it is worth mentioning that the present article is the first report on magneto transport measurements of Sn2Pd, which show the same to be a topological material with weak superconducting phase below around 2.8 K.

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.

Study on the microstructure, electrical properties, and electric-heating performance of MWCNT/AgNW/cellulose hybrid fibers

This study reports on the microstructure, structural characteristics, thermal stability, electrical property, and electric-heating performance of a series of hybrid cellulose fibers. For the purpose, we alternately dip-coated cellulose fibers with multiwalled carbon nanotube (MWCNT) and silver nanowires (AgNW). The scanning electron microscopy image and X-ray diffraction patterns show that MWCNT and AgNW are sequentially coated on the surface of the cellulose fiber as the dip-coating cycle increases. This result is validated by the fact that the electrical conductivity of the MWCNT/AgNW/hybrid cellulose fiber increases by 0.23 S/cm from 3.94 × 10−9 S/cm in the longitudinal direction as the coating cycle increases after the seventh final coating. These results indicate that a highly effective and conductive MWCNT/AgNW network is layer-by-layer created on the cellulose fiber. This fiber exhibits stable electric-heating performance at a heating range of 2 × 3 cm for a network that is knitted using rib- and garter-stitches.

Quantum confinement and effective masses dependence in black phosphorus quantum dots and phosphorene

In the present study, quantum confinement effect in phosphorene and black phosphorus quantum dots is extensively studied from experimental and theoretical viewpoints. These quantum structures were prepared with the help of Benzonitrile solvent using Liquid Phase Exfoliation and solvothermal-assisted Liquid Phase Exfoliation, respectively. On one hand, Fourier-transform infrared spectroscopy shows no sign of phosphorus oxidation in both phosphorene and black phosphorus quantum dots solutions. Furthermore, Raman spectroscopy showed a shift in B2gandAg2 phonon modes for phosphorene and black phosphorus quantum dots as compared to bulk black phosphorus. On the other hand, structural characterization via high-resolution transmission electron microscopy imaging and electron diffraction patterns showed a high degree of crystallinity in both quantum structures with no sign of aggregations. Optical properties characterization showed the expected increase in the bandgap value for both quantum structures, which were supported by theoretical calculations using density functional theory and effective mass approximation. Interestingly, we demonstrate that the quantum confinement observed in phosphorene is weakened to the expected extent, relative to that in BPQDs, by the loss of two confinement dimensions. Appropriate models, describing the bandgap and effective mass dependence as a function of the confinement regime, are presented.

Polarization information landscapes expanded from single-shot images of ring-like diffraction patterns

In this paper, we propose a ring-type grating in which grating vectors formed by periodic molecular alignments are superimposed radially. Depending on incident polarization states, the anisotropic gratings generate polarization dependencies for the ring-like first order diffraction. To determine the polarization states of incident light for both single and multi-wavelengths, we attempted to extract the optical intensity distribution on the ring-like diffraction from each single-shot diffraction image. In addition, a system that enables the detection of spatial modulation of optical birefringence is proposed. Finally, we concluded that the optical intensity distribution on the circumference of the ring-like diffraction has sufficient potential to be available.

Large-scale phase retrieval

High-throughput computational imaging requires efficient processing algorithms to retrieve multi-dimensional and multi-scale information. In computational phase imaging, phase retrieval (PR) is required to reconstruct both amplitude and phase in complex space from intensity-only measurements. The existing PR algorithms suffer from the tradeoff among low computational complexity, robustness to measurement noise and strong generalization on different modalities. In this work, we report an efficient large-scale phase retrieval technique termed as LPR. It extends the plug-and-play generalized-alternating-projection framework from real space to nonlinear complex space. The alternating projection solver and enhancing neural network are respectively derived to tackle the measurement formation and statistical prior regularization. This framework compensates the shortcomings of each operator, so as to realize high-fidelity phase retrieval with low computational complexity and strong generalization. We applied the technique for a series of computational phase imaging modalities including coherent diffraction imaging, coded diffraction pattern imaging, and Fourier ptychographic microscopy. Extensive simulations and experiments validate that the technique outperforms the existing PR algorithms with as much as 17dB enhancement on signal-to-noise ratio, and more than one order-of-magnitude increased running efficiency. Besides, we for the first time demonstrate ultra-large-scale phase retrieval at the 8K level (7680times 4320 pixels) in minute-level time.