Lattice Arrangement Research Articles

In Situ Study on the Structural Evolution of Flexible Ionic Gel Sensors

With the development of society, the demand for smart coatings is increasing. The development of flexible strain sensors using block copolymer self-assembled ionic gel materials provides a promising method for promoting the development of smart coatings. The ionic liquid in the ionic part of the material is crucial for the performance of the sensor. In this study, the structural changes within FDA/dEAN (self-assembly of acrylated Pluronic F127 (F127-DA) in partially deuterated ethylammonium nitrate (dEAN)) triblock copolymer ionic gel during uniaxial tensile flow were characterized using an in situ SAXS technique. The results revealed that the characteristics of the responses of the ionic gel to strain resistance were intricately linked to the evolution of its microstructure during the tensile process. At low levels of strain, the face-centered cubic lattice arrangement of the micelles tended to remain unchanged. However, when subjected to higher strains, the molecular chains aligned along the stretching direction, resulting in a more ordered structure with reduced entropy. This alignment led to significant disruption in bridging structures within the material. Furthermore, this research explored the impact of the stretching rate on the relaxation process. It was observed that higher stretching rates led to decreases in the average relaxation time, indicating rate dependence in the microstructure’s behavior. These findings provide valuable insights into the behavior and performance of flexible strain sensors based on ionic gel materials in smart coatings.

Tunability of domain structure in partially inverse spinels NiAl2O4

Re-arrangement of cationic distribution in partially inverse spinel NiAl2O4 by using chemical pressure perturbation is studied. Structural, impedance and magnetic analysis suggest presence of regions/domains inside the grain/bulk with same lattice arrangement but varying in cationic oxidation state. Perturbing the cationic distribution in the grain via low concentrations of ambivalence substituent rearranges the cationic distribution across these domains within the partially inverse spinel lattice without disturbing the crystal structure. A comprehensive explanation on the origin & tunability of cationic distribution within the partially-inverse lattice is proposed.

Numerical study on heat transfer deterioration of supercritical CO2 in lattice structure array channel

This study numerically explores the fluid flow and heat transfer features of supercritical carbon dioxide (CO2) in lattice structure array channel. The mitigation mechanism of the miniature cylindrical lattice structure array on heat transfer deterioration (HTD) of supercritical CO2 in vertically upward heated channel is studied. This paper evaluates the effect of several key influential parameters (length, diameter, pitch and number) of cylindrical lattice structure array on fluid flow field involving vortex structures, heat transfer coefficient, buoyancy effect and accelerated effect. The results indicate that the lattice structure can effectively suppress the HTD by generating the vortex structure which promoting the turbulent mixing effect and enhancing the turbulent kinetic energy (TKE) of the fluid. Compared with the smooth channel, the peak wall temperature of the lattice structure channel is reduced by about 50 °C, with a corresponding increase in the heat transfer coefficient of about 140 %. The average heat transfer coefficient of the channel is increased by more than 1/3. Furthermore, by increasing lattice length can reduce flow layer stratification and by increasing lattice diameter can creating a composite vortex, which enhance flow mixing strength. The larger the lattice pitch, the worse the overall suppression effect. A denser lattice arrangement produces more temperature valleys, thereby increasing the heat transfer coefficient. The conclusions in this study could provide the main theory support for security and stability of supercritical CO2 heat exchangers in power system.

Multifunctional topological photonic crystal device for multichannel frequency routing and highly sensitive refractive index sensing

We propose a novel photonic crystal (PC) structure with C-4 symmetry of the square lattice that utilizes topological edge states (TESs) to achieve multichannel frequency routing and high-sensitivity refractive index (RI) sensing. The proposed system combines trivial and nontrivial unit cells to form a unique lattice arrangement that supports multiple TESs. These states enable the realization of seven distinct output ports, each capable of transmitting a specific frequency, significantly enhancing optical communication systems’ bandwidth and data transfer capabilities. This feature makes the proposed PC structure an ideal candidate for multichannel frequency routing applications. Additionally, the structure incorporates a central cavity that exhibits robust light localization, making it highly sensitive to changes in the surrounding medium’s refractive index. Simulations demonstrate that the proposed structure can achieve RI sensing sensitivity of up to 721 nm/RIU, coupled with a high-quality factor exceeding 105. With its exceptional RI sensing capabilities, the proposed multichannel PC device holds immense potential for various technological advancements in frequency routing.

Ultra-High Birefringence Property and Low Confinement Loss of Circular Photonic Crystal Fiber for Telecommunication Application

Abstract: A redesigned PCF structure with minimal confinement loss and high birefringence is proposed in this research paper. It employs a circular lattice arrangement with one ring of identical air holes. High birefringence and low confinement loss are two of the properties that have been numerically studied using the finite element method with circular perfectly matched layer boundary conditions. By adjusting the hole size and spacing, it is possible to achieve both properties simultaneously. At an excitation wavelength of 1550 nm, a numerically obtained modal birefringence of 2.3179×10-2 is observed. Simultaneously, by methodically evaluating the cladding rings, the center-to-center distance between the air holes, and the number of cladding rings with equal diameters, a minimal confinement loss (<10-1) may be achieved. Additionally, the suggested PCF verifies that it is feasible to acquire. Our extremely birefringent fiber can be controllably created thanks to the development of birefringence with structural modifications. The suggested structure has better optical characteristics, making it a potential contender for sensing and broadband dispersion correction.

Thermally stable radiative recombination centers within trench structures of red multi-quantum wells

High-Indium (In)-content multi-quantum wells (MQWs) are generally thermally unstable due to poor crystal quality resulting from low-temperature growth. In this study, red emission was achieved by modulating trench structures using dual-colour MQW structures. Impressively, the red MQWs inside deep trenches showed excellent thermal stability despite being grown at low temperatures. After high-temperature annealing at 950 °C for 30 min, the photoluminescence (PL) intensity of red MQWs exhibited a significant reduction of 91.9% outside trenches, while it dropped by only 9.3% inside trenches, as confirmed by confocal PL mapping. Transmission electron microscopy results show that massive In-rich phases and stacking faults appeared in the MQWs outside trenches after annealing. By contrast, the red MQWs inside deep trenches remained intact in lattice arrangement without being significantly damaged. The superior thermal stability of red MQWs inside deep trenches was mainly attributed to the low-defect-density epitaxy of InGaN layers in strain-relaxed states.

Sm substitution induced spin reorientation and stabilization of double perovskite structure resulting in enhanced magnetoelectricity in LaYFe2O6

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.

Rational Design of Multinary Metal Chalcogenide Bi0.4 Sb1.6 Te3 Nanocrystals for Efficient Potassium Storage.

Multinary metal chalcogenides hold considerable promise for high-energy potassium storage due to their numerous redox reactions. However, challenges arise from issues such as volume expansion and sluggish kinetics. Here, a design featuring a layered ternary Bi0.4 Sb1.6 Te3 anchored on graphene layers as a composite anode, where Bi atoms act as a lattice softening agent on Sb, is presented. Benefiting from the lattice arrangement in Bi0.4 Sb1.6 Te3 and structure, Bi0.4 Sb1.6 Te3 /graphene exhibits a mitigated expansion of 28% during the potassiation/depotassiation process and demonstrates facile K+ ion transfer kinetics, enabling long-term durability of 500 cycles at various high rates. Operando synchrotron diffraction patterns and spectroscopies including in situ Raman, ex situ adsorption, and X-ray photoelectron reveal multiple conversion and alloying/dealloying reactions for potassium storage at the atomic level. In addition, both theoretical calculations and electrochemical examinations elucidate the K+ migration pathways and indicate a reduction in energy barriers within Bi0.4 Sb1.6 Te3 /graphene, thereby suggesting enhanced diffusion kinetics for K+ . These findings provide insight in the design of durable high-energy multinary tellurides for potassium storage.

Structural and spectroscopic correlation in barium-boro-tellurite glass hosts: effects of Dy2O3 doping

In this study, a series of barium-boro-tellurite glass hosts with varying concentration of Dy2O3 doping (0 to 1.25 mol%) were made by melt-quenching method. A study was conducted to investigate how Dy2O3 dopants affect the physical and spectroscopic traits of glasses. Raw materials including barium oxide (BaO), tellurium dioxide (TeO2), boron oxide (B2O3), and dysprosium oxide (Dy2O3) were used to produce these glasses. XRD patterns of the samples showed a broad hump and absence of long-range periodic lattice arrangements, indicating their amorphous nature. The Raman spectral analyses displayed the various vibration modes where the most intense band caused by BaO vibrations at 300 cm-1 and 450 cm-1 corresponding to the symmetric stretching vibration mode of Te–O–Te intra-chain bridges. The peak at 750 cm-1 was due to TeO4 and Te-O-Te vibration modes. The value of optical band gap energy was decreased from 3.155 to 2.1894 eV and then increase at higher Dy2O3 level (0.75 to 1.25 mol%). At Dy3+ contents between 0.25 to 1.25 mol% seven absorption bands were observed at 390, 424, 452, 750, 797, 895 and 1092 nm due to the electronic transitions in Dy3+. The glass refractive indices were raised from 2.3563 to 2.6584 and then decreased at higher Dy2O3 contents which was mainly because of the generation of more bridging oxygen (BO) in the glass matrix. The value of glass electronic polarizability and oxide ions polarizability calculated using LorentzLorenz equation showed a decrease with the rise of Dy2O3 contents, which was ascribed to the presence of fewer non-bridging oxygen (NBO). The optical basicity of the proposed glass hosts was calculated using Duffy and Ingram equation which was decreased with the increase of doping contents. In addition, the optical transmission was increased and reflection loss was reduced with increasing Dy+3 levels. The value of metallization parameter below 1 proved the true amorphous nature of the prepared samples. All the glasses revealed blue and yellow photoluminescence emission peaks due to 4F9/2→ 6H15/2, and 4F9/2 →6H13/2 transitions in Dy3+, respectively. The proposed glass compositions may be beneficial for the advancement of solid-state lasers.

Tuning of magnetic and dielectric properties of Gallium doped hematite(α-GaxFe(2−x)O3) nanospheres

In this work, we investigated the impact of Ga doping on the properties of α-Fe2O3 i.e. α-GaxFe(2−x)O3 (x=0.00, 0.20, 0.40, 0.60) nanospheres synthesized via novel hydrothermal technique and explored structural alterations, dielectric response, and magnetic characteristics. The hexagonal framework containing a rhombohedral lattice arrangement of α- GaxFe(2−x)O3 (x=0.00, 0.20, 0.40, and 0.60) nanoparticles has been confirmed by rigorous analysis using X-ray Diffraction (XRD) and Rietveld refinements. Nanospheres with impressive mono dispersity and an average diameter of 63 nm have been determined by scanning electron microscopy. Magnetic investigations revealed diluted antiferromagnetic spin order within Ga doped α- Fe2O3 nanoparticles marking a significant increase in the coercivity from 1595.28–2343.46 Oe (x=0.00–0.60). The observable remnant magnetization patterns illustrate the significance of Ga3+ doping in enhancing the magnetic characteristics of α-Fe2O3 attributed to the presence of uncompensated spin values between neighboring rhombohedral layers where opposite spin orientations coexist. By tracing the interactions and reversible/irreversible components, the FORC technique enabled a deeper comprehension of the magnetic response and made a substantial contribution to the interpretation of the complicated magnetic nature of the α-Ga0.20Fe1.8O3. A detailed dielectric analysis of α-GaxFe(2−x)O3 (x=0.00, 0.20, 0.40, and 0.60) nanoparticles was conducted to determine the dielectric constant (ε), dielectric loss (tanδ), ac-conductivity, complex impedance components, and the hopping probability of electron fluctuation with frequency. In the cole-cole plot for α- GaxFe(2−x)O3 (x=0.20, 0.40, and 0.60), the dominating grain boundary effect in conduction is indicated by a single semi-circle.

Predicting optical properties of different photonic crystal fibers from 2D structural images using convolutional neural network and transfer learning

An efficient and accurate joint neural network has been established to predict the optical properties of different photonic crystal fibers using two-dimensional structural images. The input variables of this network are structural images derived from the two-dimensional material refractive index distribution of the fiber cross-section. The structural images have greater flexibility and facilitate generalization research and transfer learning testing on various types of optical fibers. The generalization properties of this neural network for other photonic crystal fibers with different lattice arrangements have been investigated, and the corresponding transfer learning method is also proposed. With this transfer learning method, only a small amount of data is required to train and update the parameter weights of the last fully connected hidden layers. As a result, efficient and accurate prediction performance can be achieved for other photonic crystal fibers with different lattice arrangements. The proposed joint neural network and the transfer learning method are flexible and efficient, which provide new approaches for more flexible optimization and reverse design of optical fiber structures in the two-dimensional parameter space.

Probing Polymorphic Stacking Domains in Mechanically Exfoliated Two-Dimensional Nanosheets Using Atomic Force Microscopy and Ultralow-Frequency Raman Spectroscopy.

As one of the key features of two-dimensional (2D) layered materials, stacking order has been found to play an important role in modulating the interlayer interactions of 2D materials, potentially affecting their electronic and other properties as a consequence. In this work, ultralow-frequency (ULF) Raman spectroscopy, electrostatic force microscopy (EFM), and high-resolution atomic force microscopy (HR-AFM) were used to systematically study the effect of stacking order on the interlayer interactions as well as electrostatic screening of few-layer polymorphic molybdenum disulfide (MoS2) and molybdenum diselenide (MoSe2) nanosheets. The stacking order difference was first confirmed by measuring the ULF Raman spectrum of the nanosheets with polymorphic stacking domains. The atomic lattice arrangement revealed using HR-AFM also clearly showed a stacking order difference. In addition, EFM phase imaging clearly presented the distribution of the stacking domains in the mechanically exfoliated nanosheets, which could have arisen from electrostatic screening. The results indicate that EFM in combination with ULF Raman spectroscopy could be a simple, fast, and high-resolution method for probing the distribution of polymorphic stacking domains in 2D transition metal dichalcogenide materials. Our work might be promising for correlating the interlayer interactions of TMDC nanosheets with stacking order, a topic of great interest with regard to modulating their optoelectronic properties.

Assessing the Impact of Genotype-by-Environment Interactions on Agronomic Traits in Elite Cowpea Lines across Agro-Ecologies in Nigeria

The yield of cowpea varieties is affected by environmental variability. Hence, candidate varieties must be tested for yield stability before release. This study assessed the impacts of genotypes, environments, and their interaction on the performance of elite cowpea lines for key adaptive, grain yield, and associated traits across different locations. A total of 42 elite genotypes were evaluated in five Nigerian environments, representing various savanna ecologies, during the 2021 growing season. The experimental design employed was an alpha lattice arrangement, with each genotype replicated three times. The results revealed significant differences among genotypes, environments, and genotype-by-environment interaction (G × E) for most traits, including days to maturity, 100-seed weight, and grain yield. The genotype and genotype-by-environment interaction (GGE) biplot showed G21 (IT14K-2111-2) and G25 (IT15K-2386-1) as the most stable genotypes across the five environments, G41 (IT11K-61-82) was best adapted to Ibadan and Shika, G5 (245-1) was best adapted to Bagauda and Gumel, and G30 (IT16K-2365-1) was best adapted to Bauchi. G21 (IT14K-2111-2) and G25 (IT15K-2386-1) could be recommended across the five test environments, whereas G41 (IT11K-61-82), G30 (IT16K-2365-1), and G5 (245-1) were specific to the adapted environments.

Regulating magnetic skyrmions in multiferroic monolayer MnOBr.

Two-dimensional multiferroic materials that exhibit both ferroelectricity and ferromagnetism provide a new platform for the discovery and regulation of magnetic skyrmions. In this study, we utilize first-principles calculations and Monte Carlo simulations to explore the properties and regulation of magnetic skyrmions in a novel multiferroic monolayer, MnOBr. MnOBr exhibits skyrmions without the need for an external magnetic field. Upon applying an external magnetic field, we found the disappearance of labyrinth domains and the formation of a periodic arrangement of the skyrmion lattice. By employing machine learning techniques, we depict a phase diagram of MnOBr under varying magnetic fields and biaxial strain, which provides a detailed depiction of phase transitions of spin textures in monolayer MnOBr. Furthermore, in MnOBr/CdClBr heterostructures, we demonstrate that the creation and annihilation of magnetic skyrmions can be controlled by switching the polarization direction of the Janus CdClBr. These findings show potential applications of MnOBr as a 2D magnetic skyrmion material in spintronic devices.

Optical and radiation shielding characteristics of Dy2O3 doped B2O3–TeO2–BaO glasses

Glass samples with varying compositions was prepared by standard approach. The composition of the samples was (50-x) B2O3–25TeO2–25BaO-xDy2O3, with x ranging from 0 to 1.25 mol%. XRD profiles confirmed that the samples were amorphous, as there were no long-range lattice arrangements observed. The successful preparation of amorphous samples was further confirmed by the absence of sharp lines & peaks. The optical properties of the obtained samples were analyzed. That a decrease in Eopt values resulted in a higher value of the refractive index (n) for the glasses. However, when the concentration of Dy2O3 exceeded certain levels (0.75, 1, and 1.25 mol%), the refractive index (n) decreased due to an increase in Eopt values. Experimental measurements using a NaI(Tl) detector were conducted to determine the radiation shielding parameters (LAC and MAC), as well as the (HVL), (TVL), & (MFP) of the glasses against gamma rays emitted by 137Cs and 60Co isotopes at energies of 0.662, 1.173, and 1.333 MeV. Excellent agreement was observed when comparing the experimental results with theoretical calculations using Phy-x/PSD software program. This suggests that the fabricated glasses have great potential for various applications in the field of optics and can effectively shield against radiation.

MXene-antenna electrode with collective multipole resonances.

Two-dimensional transition metal carbides and nitrides (MXene-s) are the focus of extensive research due to their exceptional potential for practical applications. We study nanostructured MXene layers to design photodetector electrodes and increase their response through hot-electron generation. We demonstrate that the lattice arrangement plays a crucial role in exciting strong optical resonances in the nanostructured MXene, specifically Ti3C2Tx, despite its high loss and weak optical resonances in an isolated antenna. We use numerical simulations and analytical calculations with coupled dipole-quadrupole lattice sums for designing photodetector electrodes. We also provide proof-of-concept experimental demonstration of the enhanced resonances even for the case of lossy materials. We report on the excitation of strong lattice resonances of the MXene antenna array with enhanced absorption, resulting in a more efficient generation of hot electrons. Our findings reveal that a multi-period array of MXene antennas can improve narrowband and broadband photodetector functionality. We propose highly efficient absorbers based on MXene metasurfaces and transforming electrodes into hybrid photodetectors using MXene antennas to enhance their performance.

Removal of metal impurities from diamond wire saw silicon powder by vacuum electromagnetic directional solidification

The utilization of high-purity silicon (∼99.9999 %) is prevalent in the solar photovoltaic sector, and achieving a reduction in its cost has emerged as a pivotal engineering objective within the silicon solar industry. Recycling silicon from diamond wire saw silicon powder (DWSSP) is a promising solution to fulfill the continuously expanding of high purity silicon demand. Vacuum directional solidification technology using high-frequency electromagnetic induction heating was proposed to purify DWSSP for the first time efficiently. The silicon melt and gas interface reaction, as well as metal impurities’ microsegregation in silicon ingot were observed. The effects of vacuum level and electromagnetic force on the separation of silicon and metal impurities were investigated using thermodynamics and electromagnetic mechanics. Results indicate that the content of oxygen in the silicon reduced from 30.91 wt% to 5.08 wt%, and the actual sample composition including for uptake of residual gas contamination steadily declined as the vacuum level increased from 600 Pa to 10 Pa. Vacuum electromagnetic directional solidification reduced the content of metal impurities from 641 ppmw to 29.80 ppmw, increases the proportion of crystalline silicon area, and makes the silicon lattice arrangement more regular.

A new mixed-ligand mononuclear Co(II) complex derived from 4,4,4-trifluoro-1-phenylbutane-1,3-dione and 1,10-phenanthroline: Synthesis, structural elucidation and quantum-computational studies

In this study, a novel mixed-ligand mononuclear Co(II) complex, denoted as {[Co(TFPBD)2(PHE)]DMF}, was synthesized and characterized using single crystal X-ray diffraction analysis. The central cobalt atom coordinated with two 4,4,4-trifluoro-1-phenylbutane-1,3-dione ligands (TFPBD1 and TFPBD2) and a 1,10-phenanthrene (PHE) ligand, adopting a slightly distorted octahedral geometry. Notably, the non-planar characteristics of the ligands led to the manifestation of non-covalent interactions within the molecular structure, further enhanced by the involvement of the lattice DMF solvent. The crystal lattice arrangement in the {[Co(TFPBD)2(PHE)]DMF} complex was a result of diverse non-covalent interactions, including hydrogen bonds, C-F…π, and Π…π stacking interactions, influenced the crystal's stability. Additionally, the study delved into the unique lattice arrangement consisted of pairwise R12(5) ring motifs along with one-dimensional molecular arrays formed along the crystallographic axes. Furthermore, intermolecular C-F…π Cg…Cg interactions resulting in two-dimensional linear molecular arrays along the a- and b-axes. Quantum computational studies using density functional theory (DFT) were employed to examine the complex's electronic structure and stability and reactivity, highlighting electron-rich and electron-deficient regions. Hirshfeld surface analysis (HSA) and Non-covalent interaction analysis confirmed the significance of intermolecular interactions where 2D fingerprint plots emphasized the prominence of CH…F interactions within the crystal structure. These findings contribute significantly to our understanding of mixed-ligand metal complexes and their potential applications in various scientific domains.

Optimization of the effect of sinusoidal phase shift heating on mixed convective in an enclosure: LBM approach

This paper investigates the influence of mixed convective heat transfer in a two-dimensional enclosure with sinusoidal heat applied on the vertical walls by the Lattice Boltzmann Approach. Governing equations are resolved by the Single-Relaxation-Time Bhatnagar-Gross-Krook model. A two-dimensional, nine-directional lattice arrangement is chosen to attain better numerical stability with good accuracy. The results are presented for four different fluids having Prandtl numbers equal to 0.015, 0.7, 1.38, and 7.0 respectively for mercury, gaseous ammonia, noble gases, and water. This analysis is performed for selected Reynolds numbers (100 ≤ Re ≤ 2000) and Richardson numbers (0.0 ≤ Ri ≤ 10.0). The above parameters are optimized using the Design of the Experiment to achieve maximum heat transfer rate. Taguchi method is used to conduct the required numbers of numerical studies and the dominant parameters are quantitatively found using Analysis of Variance (ANOVA). The present numerical results are compared with the existing literature and found good agreements. Results show that the right-side wall has always a higher heat transfer rate than the left-side wall. The factor levels combination for maximum heat transfer rate is found as Pr = 7.0, Re = 2000, and Ri = 10.

Preparation and Unique Three-Dimensional Self-Assembly Property of Starfish Ferritin.

The structure and assembly properties of ferritin derived from aquatic products remain to be explored. Constructing diverse three-dimensional (3D) protein architectures with the same building blocks has important implications for nutrient delivery, medicine and materials science. Herein, ferritin from Asterias forbesii (AfFer) was prepared, and its crystal structure was resolved at 1.91 Å for the first time. Notably, different from the crystal structure of other reported ferritin, AfFer exhibited a BCT lattice arrangement in its crystals. Bioinspired by the crystal structure of AfFer, we described an effective approach for manufacturing 3D porous, crystalline nanoarchitectures by redesigning the shared protein interface involved in different 3D protein arrays. Based on this strategy, two 3D superlattices of body-centered tetragonal and simple cubicwere constructed with ferritin molecules as the building blocks. This study provided a potentially generalizable strategy for constructing different 3D protein-based crystalline biomaterials with the same building blocks.