Structural Properties Research Articles

The Structural, Electronic and Vibrational Properties of LaCrO . A Quantum Mechanical Investigation by Using an All Electron Gaussian Type Basis Set and a Full Range Hybrid Functional.

The geometrical, electronic and vibrational properties of LaCrO have been investigated by using an all electron Gaussian type basis set, the B3LYP functional and the CRYSTAL code, and compared with KVF : in the two compounds the transition metal is formally in d configuration. The high spin t ground state excludes the Jahn Teller deformation and the orbital ordering. The energy gain due to the rotation of the octahedra (from the cubic space group Pm , N. 221, to space group , N.127, and to , N. 140) in the oxide is about 70 times larger than in the fluoride (5.4 vs. 0.08 mE ), due to the larger electrostatic forces (a factor four, as the formal charge doubles in going from F- to O2-) and the consequently reduced B-X distances. In KVF , the p states of fluorine are separated by 6.4 eV from the d states of vanadium, whose band is quite narrow (1 eV). In the oxide, on the contrary, the oxygen p states overlap to a large amount with the d states of chromium, whose band is more than 6 eV large. The FM and AFM energy differences, the spin density maps and profiles, and the Mulliken analysis data are also provided for documenting the differences between the oxide and the fluoride.

Dielectric Properties of Water with a Low Quantity of NaCl inside Charged Nanoslits.

A 0.5 molal solution of NaCl in water confined within charged graphene nanoslits represents an intriguing system for molecular dynamics simulation, functioning as a model for a nanocapacitor. This charged configuration not only holds practical significance for the advancement of nanoscale capacitors but also offers valuable insights into how the charged walls and applied electric field influence the structure of water, the movement of ions within the solution, and how these alterations in water impact the overall fluid behavior. The behavior of the solution under nanoconfinement diverges markedly from that observed in bulk conditions, exhibiting distinct structural, dynamic, and dielectric properties. The charging of the graphene nanoslits generates an electric field within the nanopore, which plays a critical role in modulating molecular interactions. Key properties, including the static dielectric constant, polarization, and density of the 0.5 molal solution, are systematically examined through the molecular structure of the confined system. The models employed in this study include the flexible FAB/ϵ model of water, which effectively reproduces various experimental properties of water under different pressure and temperature conditions. Additionally, the NaCl/ϵ model is used, which also captures a range of experimental characteristics associated with sodium chloride solutions. Together, these models facilitate a comprehensive understanding of the complex behavior of water and ions under the influence of nanoconfinement and electric fields, providing insights that are essential for both fundamental science and practical applications in nanotechnology.

A comprehensive review of yttrium aluminum nitride: crystal structure, growth techniques, properties, and applications

YAlN has emerged as a wide band gap semiconductor with high potential to compete with ScAlN in industrial applications. Theoretical predictions about YAlN’s material properties have been the main motivation for conducting experimental investigations and verify simulated results. However, several challenges have been faced in experimental studies on YAlN that contradict theoretical data, especially when trying to reach higher alloy concentrations. This work presents a systematic review analyzing different material properties including structural characterization, elastic properties, and thermal features. It combines all available experimental data on the growth and reported material parameters, such as band gap, lattice parameters, and electrical properties with the aim of introducing a new motivation to further study YAlN’s potential in various fields of device applications. The review provides a comprehensive overview on the current state of knowledge on YAlN, highlighting the discrepancies between theoretical predictions and experimental results. By providing information from multiple studies, this work offers valuable insights into the challenges and opportunities associated with YAlN development, paving the way for future research directions and potential industrial applications of this promising wide band gap semiconductor.

Impact of Slickwater Fracturing Fluid on Pore Structure and Micromechanical Properties of Clay-Rich Shale Using Fluid Intrusion and AFM Experiments

Impact of Slickwater Fracturing Fluid on Pore Structure and Micromechanical Properties of Clay-Rich Shale Using Fluid Intrusion and AFM Experiments

Role of metal-organic frameworks (MOFs) in electrochemical energy storage devices including batteries and supercapacitors

Abstract Better energy storage systems are becoming more and more in demand as electric cars, portable electronics, and renewable energy sources become more prevalent. Supercapacitors and batteries, such as lithium-ion batteries (LIBs), sodium-ion batteries (NIBs), lithium sulfur/air batteries, and lithium selenium batteries, are major components of these technologies; yet, stability, cycle life, and energy density are some of the challenges they face. MOFs have emerged as a new material that can solve the problems with unique structural properties. Large surface area and porosity are properties of MOFs which improve the energy density, life cycle and stability of energy storage devices when MOF are used as alectrode material in these devices.This paper analyzes and focuses on the application of MOFs in supercapacitors, LIBs, and SIBs, in which it emphasizes improvement in terms of stability and performance. This review article ends with an overview of the important challenges and the prospects for future research to fully meet the promise of Metal organic frameworks in energy storage applications.

Optimizing the myofibrillar-plant proteins emulsion by ultrasound techniques: Improvements in structural and functional properties.

The integration of myofibrillar proteins with plant proteins has gained substantial consideration in the food industry for producing healthier and more sustainable food products. However, achieving the desired properties of these protein emulsions remains challenging. High-intensity ultrasound treatment has emerged as a promising method to enhance the structural and functional properties of emulsions. We have explored the previously unexamined potential of ultrasonication with respect to improving the stability of animal-plant-based protein emulsions, providing new insights into the interactions of novel protein combinations. Ultrasonication improved the stability of the myofibrillar protein-soybean protein isolate (MS), myofibrillar protein-pea protein (MP) and myofibrillar protein-hydrolyzed wheat protein (MW) emulsions. Interestingly, the particle size of MS, MP and MW emulsions was significantly reduced with ultrasound treatment for 20 min. Among the three protein combinations, MW presented better stability, as indicated by the higher zeta potential, lower particle size and turbidity values. Moreover, the stability of MW was increased with an increasing ultrasound time. The stability of MW was significantly improved after 10 min of ultrasound treatment as a result of improving the zeta potential, particle size and turbidity values, changing the secondary structure and microstructure of the emulsion. © 2025 Society of Chemical Industry.

Solar Modulation of Cosmic Nuclei over a Solar Cycle: Results from the Alpha Magnetic Spectrometer

We report the properties of precision time structures of cosmic nuclei He, Li, Be, B, C, N, and O fluxes over an 11-year solar cycle from May 2011 to November 2022 in the rigidity range from 1.92 to 60.3 GV. The nuclei fluxes show similar but not identical time variations with amplitudes decreasing with increasing rigidity. In particular, below 3.64 GV the Li, Be, and B fluxes, and below 2.15 GV the C, N, and O fluxes, are significantly less affected by solar modulation than the He flux. We observe that these differences in solar modulation are linearly correlated with the differences in the spectral indices of the cosmic nuclei fluxes. This shows, in a model-independent way, that solar modulation of galactic cosmic nuclei depends on their spectral shape. In addition, solar modulation differences due to nuclei velocity dependence on the mass-to-charge ratio (A/Z) are not observed. Published by the American Physical Society 2025

Study of attenuation characteristics for novel neonatal head phantom in diagnostic radiology using Monte Carlo simulations and experiments.

This study presents the design and validation of a neonatal head phantom using innovative heterogeneous composite materials customized to replicate the X-ray attenuation properties of neonatal cranial structures. Analysis of Hounsfield Unit (HU) data from 338 neonatal head CT scans informed the design of epoxy resin-based composites with additives such as sodium bicarbonate, fumed silica, and acetone to simulate bone, brain matter, cerebrospinal fluid (CSF) and hyperdense abnormalities. The cranial bone substitute (60% epoxy resin, 40% sodium bicarbonate) achieved a density of 1.60 g/cm³, with HU values (574.67-608.04) closely matching clinical ranges. Brain matter (95% epoxy resin, 5% acetone) achieved HU values (35.27-43.61), aligning with clinical means, while the CSF-equivalent material (80% epoxy resin, 15% fumed silica, 5% acetone) matched neonatal CSF HU values (14.53-17.02). A mass substitute for hyperdense abnormalities exhibited HU values (56.16-61.07), enabling differentiation from normal brain. Validation included Monte Carlo simulations and experimental CT imaging, showing close agreement in linear attenuation coefficients, with deviations below 11% across energy levels. Mass attenuation coefficients from simulations and XCOM software were consistent, with deviations under 0.7%, confirming the materials dosimetric reliability. The phantom, with a cylindrical geometry (9 cm diameter, 10 cm length), provides accurate attenuation properties across 80-120 kVp energy levels, with deviations below 5% between experimental CT numbers and simulation data. This phantom offers a robust platform for neonatal imaging research, enabling impactful dose optimization and imaging protocol adjustment and supports improved diagnostic accuracy in pediatric imaging.

Warpage in wafer-level packaging: a review of causes, modelling, and mitigation strategies

Wafer-level packaging (WLP) is a pivotal semiconductor packaging technology that enables heterogeneously integrated advanced semiconductor packages with high-density electrical interconnections through its efficient and highly reliable manufacturing processes. Within this domain, fan-out wafer-level packaging has gained prominence due to its potential for high integration capacity, scalability, and performance on a smaller footprint. This review examines FOWLP technology and its associated challenges, primarily warpage. As semiconductor companies strive to develop cutting-edge packages, wafer warpage remains an intrinsic and persistent issue affecting yield and reliability at both the wafer and package levels. Warpage characterization techniques and modeling approaches, including theoretical, numerical, and emerging artificial intelligence and machine learning (AI/ML) methods, have been analyzed. The structural parameters and properties of the constituent materials of the reconstituted wafer and the FOWLP process have been considered to evaluate the effectiveness of these methods in predicting and analyzing warpage. Potential directions and limitations in warpage prediction and mitigation have been outlined for future research for more reliable and high-performance FOWLP solutions.

Crystal structure modulating performances for 213-nm GeO2 solar-blind photodetectors via DC reactive magnetron sputtering method

Owing to the ultra-wide bandgap energy, high thermal conductivity, and ambipolar capability, GeO2 films are receiving great attention for potential applications in power devices and solar-blind photodetectors. However, the precise control of the crystal structure and optical property is a huge challenge due to close free formation energies of multiple phases, inhibiting the GeO2 based practical device applications. Here, we have fabricated quartz and rutile-GeO2 thin films utilizing the magnetron sputtering based synthetic strategy, which exhibit ultra-wide bandgap energies of 5.51 and 5.88 eV. On the foundation of these ultra-wide bandgap semiconductors, obvious photoresponse characteristics have been achieved at 213 nm and the quartz-GeO2 device exhibits better performances including a short fall time of 148.5 ms, a high photo-dark current ratio of 86.65, large photoresponsivity of 4.56 A/W, and high detectivity of 6.78 × 1013 Jones, which can be attributed to the less oxygen defect exists in the quartz-GeO2 film due to the oxygen-rich growth condition and the better lattice matching with sapphire. Our findings suggest that the GeO2 thin film is a candidate material for optoelectronic device applications and will provide a facile and innovative strategy to develop the solar-blind photodetector.

Oxazolo[5,4-d]pyrimidines as Anticancer Agents: A Comprehensive Review of the Literature Focusing on SAR Analysis

Oxazolo[5,4-d]pyrimidines have been found to exhibit a wide range of biological activities, including the inhibition of various enzymes and signaling pathways associated with carcinogenesis. The objective of this review is to demonstrate that the oxazolo[5,4-d]pyrimidine scaffold represents a valuable structure for the design of novel anticancer therapies. The article provides a comprehensive overview of the chemical structure and pharmacological properties of oxazolo[5,4-d]pyrimidine derivatives, drawing upon the literature and international patents from 1974 until the present. Notably, the review explores structure–activity relationships (SAR) with a view to enhancing the therapeutic efficacy of oxazolo[5,4-d]pyrimidines.

Sulfur Vacancy-Induced Enhancement of Piezocatalytic H2 Production in MoS2.

This study explores the role of S vacancies in MoS2 in enhancing its piezocatalytic efficiency. Sulfur vacancies in the crystal lattice introduce localized changes in the electronic structure and charge distribution, improving the material's piezoelectric response. Characterization of the catalysts involved techniques like field-emission scanning electron microscopy (FESEM), X-ray diffraction (XRD), transmission electron microscopy (TEM), and X-ray photoelectron spectroscopy (XPS). Electrochemical measurements, including impedance spectroscopy (EIS) and Mott-Schottky (M-S) analysis, are performed to assess the piezocatalytic performance. The study also employed density functional theory (DFT) calculations to investigate the electronic structure and hydrogen adsorption properties of MoS2 with S vacancies. The results demonstrated that S-deficient MoS2 significantly enhanced piezocatalytic H2 evolution. The piezocatalytic H2 production rates of MoS2 with different vacancy concentrations are measured under ultrasonic vibration. The sample with an optimal vacancy concentration (MS-1) exhibited the highest H2 production rate of 1423.29µmol g-1 h-1, compared to 439.06µmol g-1 h-1 for pristine MoS2 (MS-0). The improved performance is attributed to the increased piezoelectric polarization and efficient charge separation facilitated by S vacancies.

Predicted thermodynamic structural and elastic properties of SrCuP and SrCuSb for thermoelectric applications

The Pseudopotential method coupled with plane waves implemented in the quantum espresso code was used in the prediction of the structural parameters and elastic constants of SrCuX (X = P, Sb) materials. The obtained results of lattice parameters and bulk modulus at equilibrium agree well with their experimental and theoretical data cited in the literature. The calculated Young’s modulus of SrCuX (X = P, Sb) aggregate thermoelectric materials are 109.25 GPa and 78.22 GPa, while their Debye temperatures are 364.2 K and 261.8 K. The vibration energy of phonons is 24.14 kJ/mol and 23.37 kJ/mol for SrCuP and SrCuSb. Our thermodynamic parameters increase monotonically with temperatures for both SrCuP and SrCuSb materials. To the best of our knowledge, there are no data available in the literature on the elastic and thermodynamic parameters of SrCuX (X = P, Sb) compounds, then our results are prediction. The absence of virtual phonon frequencies indicates high dynamic stability in both materials, with a band gap about 1 THz between optical and acoustic phonons in SrCuP and SrCuSb.

Powering the Future: Opportunities and Obstacles in Lead-Halide Inorganic Perovskite Solar Cells.

Efficiency, stability, and cost are crucial considerations in the development of photovoltaic technology for commercialization. Perovskite solar cells (PSCs) are a promising third-generation photovoltaic technology due to their high efficiency and low-cost potential. However, the stability of organohalide perovskites remains a significant challenge. Inorganic perovskites, based on CsPbX₃ (X = Br-/I-), have garnered attention for their excellent thermal stability and optoelectronic properties comparable to those of organohalide perovskites. Nevertheless, the development of inorganic perovskites faces several hurdles, including the need for high-temperature annealing to achieve the photoactive α-phase and their susceptibility to transitioning into the nonphotoactive δ-phase under environmental stressors, particularly moisture. These challenges impede the creation of high-efficiency, high-stability devices using low-cost, scalable manufacturing processes. This review provides a comprehensive background on the fundamental structural, physical, and optoelectronic properties of inorganic lead-halide perovskites. It discusses the latest advancements in fabricating inorganic PSCs at lower temperatures and under ambient conditions. Furthermore, it highlights the progress in state-of-the-art inorganic devices, particularly those manufactured in ambient environments and at reduced temperatures, alongside simultaneous advancements in the upscaling and stability of inorganic PSCs.

Cu Intercalation-Stabilized 1T' MoS2 with Electrical Insulating Behavior.

The intercalated two-dimensional (2D) transition metal dichalcogenides (TMDCs) have attracted much attention for their designable structures and novel properties. Among this family, host materials with low symmetry such as 1T' phase TMDCs are particularly interesting because of their potentials in inducing unconventional phenomena. However, such systems typically have low quality and poor stability, hindering further study of the structure-property relationship and applications. In this work, we intercalated Cu into 1T' MoS2 with high crystallinity and high thermal stability up to ∼300 °C. We identified the distribution and arrangement of Cu intercalators for the first time, and the results show that Cu intercalators occupy partially the tetrahedral interstices aligned with Mo sites. The obtained Cu-1T' MoS2 exhibits an insulating hopping transport behavior with a large temperature coefficient of resistance reaching -4∼-2%·K-1. This work broadens the artificial intercalated structure library and promotes the structure design and property modulation of layered materials.

Functionalization of [C60]-Fullerene: A Recent Update.

Functionalization of fullerene has garnered great attention owing to its unique structural, electronic, and photophysical properties. The distinctive properties of fullerene derivatives make them a multifaceted candidate for application in photochemical, biological, nanomaterial, and photophysical studies. The radical scavenging properties of fullerene owe them an important role in reactive oxygen species (ROS) capturing applications. The organic photovoltaic cells are fabricated utilizing functionalized fullerenes due to its electron-accepting properties. The increased prominence of functionalization led to different innovative methodologies to bloom. The present review focuses on various strategies employed for functionalization to synthesize carbo- and heterocycles fused fullerenes from early 2014 to till date.

Structural and spectroscopic properties of Hydrothermally Synthesized α-GaO(OH) Structures: Impact of Annealing Temperatures

Abstract This work investigated the structural and spectroscopic properties of a-GaO(OH) prepared via a hydrothermal method. The film was heat treated at three different temperatures, which are 350, 450, and 550°C. The films were characterized by X-ray diffraction, field-emission scanning electron microscopy, UV-VIS spectroscopy, Raman spectroscopy, and X-ray photoelectron spectroscopy. The morphology of the prepared α-Ga₂O₃ films shows rhombus nanorod structure, which is a favorable morphology for advanced applications. Raman spectroscopy confirmed the rhombus structure of α-Ga₂O₃ nanocrystals at lower temperatures and indicated adjustments in the lattice vibrations and crystal structure with increasing annealing temperature up to 550°C. The optical band gap of α-Ga₂O₃ was estimated using diffused reflectance and Tauc plot analysis. The results showed that the band gap decreased from 5.15 to 4.52 eV with increased heat treatment due to reduced defects and improved crystalline structure.

Extendable Synthesis of Organic Cations for In Situ Construction of Hybrid Metal Halideswith Near-Unity Photoluminescenceand Strong Second Harmonic Generation.

The A-site organic components of organic-inorganic hybrid metal halides (OIHMHs) significantly impact their crystal structure and optoelectronic properties. However, chemical modification of A-site cations has been mostly limited to commercial organic precursors, which restricts thestructural variability of OIHMHs for optimal functionalities. Herein we have proposed an extendable synthesis approach to the direct procurability of various organic cations with desireable structures for the in situ construction of a library of OIHMH materials. The template condensation reaction between dimethyl sulfoxide and acetone derivatives yields A-site organic cations with exquisite control of modularization and regioselectivity within the OIHMH crystallization system. The as-fabricated OIHMHs demonstrated highly efficient linear optical photoluminescence or nonlinear optical second harmonic generation,promising potential applications in photonic devices. This in situ synthetic strategy offers a structural extension of OIHMHs and establishes afundamental methodological platform for screening functional OIHMH materials.

Structure-Induced Reversing Basicity of α-Anionic Fischer Carbenes.

Group VI metal carbenes and their α-anionic complexes play an important role in organic synthesis, yet structural characterizations and thermodynamic studies for reactive α-anions remain challenging. This work investigated the molecular structures and thermodynamics of α-anionic Fischer carbenes and their conjugated acids. The results clarify the negative charge localized on the M(CO)5 moiety and the C═X (X = C, N, or O) double bond in all anionic structures. The conjugation between the π-donating group and the M(CO)5 moiety significantly lowers the energy of neutral complexes, resulting in a reversing acidity between α-methyl, amino, and hydroxyl groups. This study deepens our understanding of the molecular structure, electronic structure, and thermodynamic property of Fischer carbenes.

Enhanced Interfacial Polarization Loss of FeS/MoS2@N‐Doped Carbon Sandwich‐Walled Nanotubes Enables High‐Performance Electromagnetic Wave Absorption

AbstractMultiple interfaces and hollow structures are vital to high‐performance electromagnetic wave (EMW) absorption of absorbers. However, it remains difficult to construct and tune such structures, and there is limited understanding regarding the relationships between their structural and dielectric loss properties. Herein, the theoretical simulations for the EMW absorption performance of the hollow sandwich and solid double‐layer structures are first carried out and it is found that the former exhibits a more pronounced power loss density than the latter. Then, a ligand‐exchange strategy following a vulcanization process to fabricate FeS/MoS2@N‐doped carbon sandwich‐walled nanotubes (FeMoS‐SWCNTs) is dveloped. The experimental results demonstrate that the FeMoS‐SWCNTs show significantly enhanced EMW absorption performance compared to the solid FeS counterparts, consistent with the simulation results. Further density functional theory calculations reveal that the enhanced dielectric properties of FeMoS‐SWCNTs are attributed to a stronger interfacial polarization resulting from electronic interactions at multiple interfaces (FeS/N‐doped carbon (NC), MoS2/NC, and FeS/MoS2), and enhanced conduction loss caused by higher density of states in the FeS/MoS2 heterostructure. These findings elucidate the relationship between the sandwich‐walled nanotube structures and their dielectric loss properties, and the developed method offers a feasible approach for the rational design of sandwich‐walled nanotubes for high‐performance EMW absorption applications.