Atomic Ratio Research Articles

Research Progress of Cu-Ni-Si Series Alloys for Lead Frames

This paper reviews the research progress of Cu-Ni-Si alloy as a lead frame material for ICs. Cu-Ni-Si alloy is considered a strong candidate for lead frame materials due to its excellent mechanical properties and adequate electrical conductivity. The types and properties of Cu-Ni-Si alloys are then discussed in detail, emphasizing strength and conductivity as two key indicators for evaluating the properties of Cu-Ni-Si alloys, as well as the challenges posed by their inverse correlation. The preparation methods of Cu-Ni-Si alloy, including conventional melting, vacuum melting, and jet forming, are also discussed, and the effects of different casting techniques on the alloy’s properties are analyzed. Furthermore, the conductivity and strengthening mechanisms of Cu-Ni-Si alloy, including solid solution strengthening, second phase strengthening, and deformation strengthening, are discussed. The effects of the Ni-Si atomic ratio, trace elements, and rare earth elements on the alloy’s properties are also discussed. Finally, the current research status of Cu-Ni-Si alloy is summarized, and future research directions are identified, including the development of new preparation technologies, establishment of systematic databases, and promotion of green manufacturing and sustainable alloy development.

Enhanced photocatalytic properties of Ge-doped Ga2O3 nanostructures synthesized via hydrothermal method

Abstract Ge-doped (1.4 at. %) β-Ga2O3 nanostructures are successfully synthesized using the hydrothermal method followed by annealing at 1000°C in an O₂ atmosphere. The crystal structures and morphologies of both intrinsic and Ge-doped β-Ga2O3 nanostructures are analyzed using high-resolution X-ray diffraction (HR-XRD), field-emission scanning electron microscopy (FE-SEM), Transmission Electron Microscope (TEM), and energy dispersive spectroscopy (EDS). Photoluminescence (PL) measurements are also performed to investigate defect-related energy levels within the bandgap. The photocatalytic activity is evaluated through the degradation of methylene blue (MB) in an aqueous solution. Ge-based precipitates form when the Ge concentration exceeds 1.4 atomic percent in the β-Ga2O3 nanostructures. As with other dopants such as Sn, Al, and Cr, this controlled incorporation of Ge significantly enhances the photocatalytic properties and potentially improves the electronic and optical properties of Ga2O3-based devices.

Evaluation of the Effect of Different Universal Adhesives on Remineralized Enamel by Shear Bond Strength and Fe-SEM/EDX Analysis

The aim of this study is to evaluate the shear bond strength of different universal adhesives applied to intact, demineralized, and remineralized enamel surfaces with total-etch and self-etch modes and to examine the effect of universal adhesives on the Ca/P mineral atomic and mass ratios of these enamel with FE-SEM/EDX (Field Emission Scanning Electron Microscopy with Energy Dispersive X-Ray Spectroscopy) analysis. For this study, 264 bovine incisors were used. Samples in the demineralized and remineralized groups were kept in demineralization solution at 37 °C for 96 h to make an artificial initial carious lesion. After demineralization, half of the demineralized samples were remineralized with MI Paste Plus. For shear bond strength (n = 144) and FE-SEM/EDX analysis (n = 120), G-Premio Bond and Clearfil S3 Bond Universal were applied on enamel surfaces with total-etch and self-etch modes, and bond strength samples were restored with resin composite. All samples were tested. The results were evaluated statistically by a three-way ANOVA test. The shear bond strength of the remineralized enamel showed high bond strength values comparable to intact enamel for universal adhesive systems. The Ca/P mineral atomic and mass ratios in remineralized enamel showed higher values than demineralized enamel, similar to intact enamel for universal adhesive systems. Initial carious lesion surfaces are unsuitable enamel surfaces for restoration. The remineralization of this surface layer before adhesive procedures may positively affect bond strength.

Enhanced photocatalytic properties of Ge-doped Ga2O3 nanostructures synthesized via hydrothermal method

Abstract Ge-doped (1.4 at. %) β-Ga2O3 nanostructures are successfully synthesized using the hydrothermal method followed by annealing at 1000°C in an O₂ atmosphere. The crystal structures and morphologies of both intrinsic and Ge-doped β-Ga2O3 nanostructures are analyzed using high-resolution X-ray diffraction (HR-XRD), field-emission scanning electron microscopy (FE-SEM), Transmission Electron Microscope (TEM), and energy dispersive spectroscopy (EDS). Photoluminescence (PL) measurements are also performed to investigate defect-related energy levels within the bandgap. The photocatalytic activity is evaluated through the degradation of methylene blue (MB) in an aqueous solution. Ge-based precipitates form when the Ge concentration exceeds 1.4 atomic percent in the β-Ga2O3 nanostructures. As with other dopants such as Sn, Al, and Cr, this controlled incorporation of Ge significantly enhances the photocatalytic properties and potentially improves the electronic and optical properties of Ga2O3-based devices.

First-principles study on electronic and optical properties of perovskite light-emitting diodes CsPb(Br1− xIx)3

CsPb(Br1−xIx)3, a mixed-halide all-inorganic perovskite, is a promising light-emitting diode (LED) material due to its impressive performance. It has been demonstrated that the mixing parameter x of halogen composition significantly influences the luminescence efficiency of CsPb(Br1−xIx)3. However, the underlying microscopic mechanisms remain unclear. Using first-principles calculations, we investigate the effects of anion mixing on the radiative and non-radiative recombination properties of perovskite materials. Simulations on the carrier mobility, exciton binding energy, affinity energy, and defect formation energy of the materials in the CsPb(Br1−xIx)3 system collaboratively revealed that a high ratio off Br is associated with enhanced luminescence efficiency. Specifically, CsPb(Br1−xIx)3 exhibits optimal luminescent performance with a 2:1 bromine-to-iodine ratio, while it shows the performance degradation with a 1:1 ratio. The results demonstrate that the ratio of halogen atoms (Br and I) has a significant influence on the LED properties of cesium-based all-inorganic perovskites CsPb(Br1−xIx)3, providing a valuable guide for the experimental preparation of cesium-based all-inorganic perovskites.

A Novel (AlCrNbTaTi)N Multilayer Hard High-Entropy Alloy Nitride Coating with Variable Aluminum Content Deposited by Cathodic Arc Ion Plating

Traditional binary coatings like TiN and CrN display limited thermal stability and wear resistance under extreme conditions. High-entropy alloy nitride (HEAN) coatings offer a promising solution due to their customizable composition and unique properties, including high hardness, corrosion resistance, and thermal stability. This study focused on (AlCrNbTaTi)N HEAN coatings to address a critical need for materials capable of enduring extreme mechanical and tribological demands by examining the impact of aluminum content on their structural and mechanical properties, providing insights for optimizing coatings in harsh conditions through a self-assembled nanolayer structure with enhanced resilience and performance. The coatings were deposited via a cathodic arc by employing an AlCrNbTaTi alloy target composed of aluminum (20, 50, 60, 70%) and equal molar ratios of Cr, Nb, Ta, and Ti. The coatings were characterized through grazing incidence X-ray diffraction, SEM, HR-TEM, a nano-indentation test, and a friction and wear test. The results indicated that with increasing Al content, the structure of (AlCrNbTaTi)N coatings shifted from FCC to an amorphous state, leading to a reduction in the hardness and elastic modulus, accompanied by an increase in the wear rate and friction coefficient. The (AlCrNbTaTi)N coating, with an equal atomic ratio of metallic elements, showed potential as a hard tool coating. It demonstrated outstanding mechanical and tribological properties, with a 34.5 GPa hardness, 369 GPa modulus, 0.35 friction coefficient, and 8.2 × 10−19 m2·N−1 wear rate. The findings highlight the potential of (AlCrNbTaTi)N coatings to extend tool life and improve operational efficiency, helping advance materials engineering for industrial applications.

Electro-Oxidation of Glycerol on Core–Shell M@Pt/C (M = Co, Ni, Sn) Catalysts in Alkaline Medium

This study explores the development of core–shell electrocatalysts for efficient glycerol oxidation in alkaline media. Carbon-supported M@Pt/C (M = Co, Ni, Sn) catalysts with a 1:1 atomic ratio of metal (M) to platinum (Pt) were synthesized using a facile sodium borohydride reduction method. The analysis confirmed the formation of the desired core–shell structure, with Pt dominating the surface as evidenced by energy-dispersive X-ray spectroscopy (EDS). X-ray diffraction (XRD) revealed the presence of a face-centered cubic (fcc) Pt structure for Co@Pt/C and Ni@Pt/C. Interestingly, Sn@Pt/C displayed a PtSn alloy formation indicated by shifted Pt peaks and the presence of minor Sn oxide peaks. Notably, no diffraction peaks were observed for the core metals, suggesting their amorphous nature. Electrocatalytic evaluation through cyclic voltammetry (CV) revealed superior glycerol oxidation activity for Co@Pt/C compared to all other catalysts. The maximum current density followed the order Co@Pt/C > Ni@Pt/C > Sn@Pt/C > Pt/C. This highlights the effectiveness of the core–shell design in enhancing activity. Furthermore, Sn@Pt/C displayed remarkable poisoning tolerance attributed to a combined effect: a bifunctional mechanism driven by Sn oxides and an electronic effect within the PtSn alloy. These findings demonstrate the significant potential of core–shell M@Pt/C structures for designing highly active and poisoning-resistant electrocatalysts for glycerol oxidation. The presented approach paves the way for further development of optimized catalysts with enhanced performance and stability aiming at future applications in direct glycerol fuel cells.

Design of Fluorescence Enhancing Sensor for Mercury Detection via Bamboo Cellulose-Derived Carbon Dots.

Mercury contamination of the environment is extremely hazardous to human health because of its significant toxicity, especially in water. Biomass-derived fluorophores such as carbon dots (CDs) have emerged as eco-friendly and cost-effective alternative sensors that provide comparable efficacy while mitigating the environmental and economic drawbacks of conventional methods. In this work, we report the fabrication of a selective fluorescence-enhancing sensor based on sulfur-doped carbon dots (SCDs) using waste bamboo-derived cellulose and sodium thiosulfate as the soft base dopant, which actively complexes with mercury ions for detection. SCDs with an average size of 4 nm were synthesized hydrothermally, and the sulfur doping was confirmed quantitatively with an atomic percentage of 6.5%. Optical studies reveal an abnormal fluorescence enhancement of SCD in the presence of mercury due to the aggregation of carbon dots via sulfur-containing functional groups. The fabricated sensor exhibits a low detection limit of 5.16 nM, suggesting its application potential as a reliable mercury sensor. Real-time analyses carried out using tap water samples spiked with mercury and industry samples showed high efficiency for Hg(II) detection. The sensing performance was also demonstrated by using SCD-coated filter paper strips.

Role of local structural distortions in the variation of martensitic transformation temperature with e/a ratio in Ni2Mn1+xZ1-x (Z = In, Sn or Sb) alloys.

Ni2Mn1+xZ1-x (Z = In, Sn or Sb) undergo martensitic transformation with transformation temperature (TM) scaling with the average valence electron per atom (e/a) ratio. However, the rate of increase of TM depends on the type of Z atom, with the slope of TMvs. e/a curve increasing from Z = In to Z = Sb. Local structural distortions are believed to be the leading cause of martensitic transformation in these alloys. A careful study of the Ni and Mn local structures in several Ni2Mn1+xZ1-x alloys with varying e/a ratio and the same Z atom, with the same e/a ratio but different Z atoms and with the same TM but with different Z atoms and different e/a ratio, revealed that the difference between Ni-Mn and Ni-Z nearest neighbor distances decreases as the Z atom changes from In to Sb. This decrease in the local structural distortion accommodates a higher content of Mn until the L21 structure becomes unstable and the alloy undergoes a martensitic transformation.

Structural, Surface, and Optical Properties of Nitrogen-Doped Al:ZnO (NAZO) Thin Films Produced by a Thermionic Vacuum Arc Deposition Technology

Nitrogen (N)-doped Al:ZnO (NAZO) thin films were deposited on glass and indium tin oxide (ITO) coated glass by a thermionic vacuum arc (TVA) technique. The structural, surface morphology, and optical properties of the produced thin films were characterized by X-ray diffractometry (XRD), atomic force microscopy (AFM), and ultraviolet-visible spectroscopy. The microstructure properties of the produced thin films on two substrates were compared, and metal oxide phases were observed in the XRD patterns and photoluminescence spectra. 2.75, 3.10, and 3.30 eV band gaps were detected. The transmittance values were approximately 90% and 60% for the film deposited onto uncoated and ITO-coated glass, respectively. According to field-emission scanning electron microscopy and atomic force microscopy images, the crystallite size is nanoscale, and its dimensions are approximately 60 and 20 nm for the film deposited onto uncoated and ITO-coated glass substrates, respectively. Atomic ratios of zinc/aluminum were 9.25/0.56, and 5.42/0.22 for uncoated and ITO-coated glass substrate, respectively. All samples were coated with the same coating process, and no post-annealing process was applied to the sample.

Synthesis of shape-tunable PbZrTiO3 nanocrystals with lattice variations for piezoelectric energy harvesting and human motion detection

PbZr0.7Ti0.3O3 cubes with tunable sizes and cuboids have been hydrothermally synthesized. PbZrTiO3 cubes with three different Zr:Ti atomic percentages were also prepared. Analysis of synchrotron X-ray diffraction (XRD) patterns reveal...

Photocatalytic degradations of organic pollutants in wastewater using hydrothermally grown ZnO nanoparticles

The increasing prevalence of organic pollutants in wastewater poses a significant environmental challenge due to their persistence and harmful effects. Photocatalysis using semiconductor nanoparticles, such as ZnO, has emerged as a promising approach for pollutant degradation, but optimizing the structural and functional properties of these materials remains a critical challenge. In this study, ZnO nanoparticles were synthesized via a hydrothermal method with varying durations (4, 6, and 8 hours) to investigate the impact of synthesis time on their photocatalytic efficiency. The structural and compositional properties were characterized using SEM, XRD, and EDS analyses, revealing that longer synthesis times improve crystallinity and alter the Zn:O atomic ratio, affecting defect density and stoichiometry. Photocatalytic performance was evaluated through the degradation of an organic pollutant under UV illumination. ZnO-6h exhibited the highest rate constant (k=0.017 min−1), outperforming ZnO-4h (k=0.016 min−1) and ZnO-8h (k=0.013 min−1). This superior activity is attributed to an optimal combination of high crystallinity, intermediate morphology, and the presence of oxygen vacancies that enhance charge carrier dynamics. The findings demonstrate that synthesis duration is a critical parameter in tuning the structural and photocatalytic properties of ZnO nanoparticles. This study provides insights into the design of ZnO-based photocatalysts and underscores their potential for environmental remediation. Future research could extend these findings by exploring scalability and pollutant-specific applications, paving the way for more efficient wastewater treatment technologies.

The energy quantization in hydrogen atom and proton-electron mass ratio in light of Symmetrical Special Relativity

The energy quantization in hydrogen atom and proton-electron mass ratio in light of Symmetrical Special Relativity

Support-Free, Connected Core-Shell Nanoparticle Catalysts Synthesized via a Low-Temperature Process for Advanced Oxygen Reduction Performance.

Nanostructured Pt-based catalysts have attracted considerable attention for fuel-cell applications. This study introduces a novel one-pot and low-temperature polyol approach for synthesizing support-free, connected nanoparticles with non-Pt metal cores and Pt shells. Unlike conventional heat treatment methods, the developed support-free and Fe-free connected Pdcore@Ptshell (Pd@Pt) nanoparticle catalyst possesses a stable nanonetwork structure with a high surface area. This approach can precisely control the atomic-level structure of the Pt shell on the Pd core at a low deposition temperature. The optimized Pd@Pt catalyst with a Pt/Pd atomic ratio of 0.8 and a Pt shell thickness of 1.1 nm exhibits a threefold improvement in oxygen reduction reaction (ORR) mass activity compared to that of commercial carbon-supported Pt nanoparticle catalyst (Pt/C). Durability evaluation demonstrated 100% retention of specific activity after 10,000 load cycles, owing to the stable nanonetwork and uniform coverage of the Pt shell. In addition, the support-free, connected core-shell nanoparticle catalyst overcomes the carbon corrosion issues commonly associated with conventional carbon-supported catalysts while simultaneously improving both ORR activity and load cycle durability. These findings highlight the potential of this innovative approach to develop support-free catalysts for polymer electrolyte fuel cells and other energy devices.

An efficient multi-gram access in a two-step synthesis to soluble, nine-atomic, silylated silicon clusters

AbstractSilicon is by far the most important semiconducting material. However, solution-based synthetic approaches for unsaturated silicon-rich molecules require less efficient multi-step syntheses. We report on a straightforward access to soluble, polyhedral Si9 clusters from the binary phase K12Si17, which contains both [Si4]4− and [Si9]4− clusters. [Si4]4− ions, characterised by a high charge per atom ratio, behave as strong reducing agents, preventing [Si9]4− from directed reactions. By the here reported separation of [Si4]4− by means of fractional crystallisation, Si9 clusters of the precursor phase K12Si17 are isolated as monoprotonated [Si9H]3− ions on a multi-gram scale and further crystallised as their 2.2.2-Cryptate salt. 20 grams of the product can be obtained through this two-step procedure - a new starting point for silicon Zintl chemistry, such as the isolation and structural characterisation of a trisilylated [MeHyp3Si9]− cluster.

The formation mechanism of metal cluster fullerenes Sc3N@Cn: force field development and molecular dynamics simulations.

Metal cluster fullerenes are a class of molecular nanomaterials with complex structures and novel properties. An in-depth study of their formation mechanism is a key topic for developing new high-yield synthesis methods and promoting the practical application of such molecular nanomaterials. To elucidate the formation mechanism of Sc3N@Cn, a representative sub-class of metal cluster fullerenes, this study developed a ReaxFF force field parameter set CNSc.ff using a single parameter optimization method and conducted systematic molecular dynamics simulations on a C-N-Sc mixed system using the newly developed force field parameter set. The results show that atomic nitrogen has strong attraction to both C and Sc atoms, and it plays a key role in the formation of Sc3N@Cn; the formation of Sc3N@Cn includes carbon cluster growth, Sc-based cluster growth and their encapsulation; temperature, carbon density, and atomic ratio all affect the relative yield of Sc3N@Cn; and the final products are a mixture of amorphous carbon, fullerenes, metallofullerenes, and metal cluster fullerenes. This study rationalizes the phenomena observed in the synthesis experiments and provides insights for the development of selective and high-yield synthesis methods for metal cluster fullerenes.

A Systematic Investigation of PbSe Thermoelectric Material

The thermoelectric characteristics of lead selenium (PbSe) doped with gallium (Ga) are investigated in this study. When the lead sulfide (PbSe) is tuned with appropriate dopants, it exhibits satisfactory ZT values, hence making it a promising thermoelectric material. This study examines the electrical conductivity, Seebeck coefficient, thermal conductivity, and power factor of PbSe, with varying amounts of added Ga. Results indicate that incorporating Ga into PbSe improves its thermoelectric performance, with a maximum ZT value of approximately 1.2 at 873 K for the optimal doping concentration of 0.005 atomic percent. This improvement is attributed to the combined effects of increased electrical conductivity and reduced thermal conductivity. These findings suggest that Ga-doped PbSe is a promising candidate for mid-temperature thermoelectric applications.

Zeolite‐impregnated polypropylene melt‐electrospun membranes for filtration applications

AbstractCombining zeolites (Zeo) through electrospinning is a developing area, with relatively few studies dedicated to the production of zeolite/polymer composites. Therefore, creating highly effective filters by using a polymer base and zeolite has become necessary. In this study, a combination of polypropylene (PP) melt and zeolite by electrospinning technique is employed to fabricate a PP‐Zeo filter membrane. The average fiber diameter of PP‐Zeo filter membrane was found as 1 ± 0.02 μm. To improve the filtration efficacy, the surface of PP/Zeo membranes was modified using zeolite by two methods, electrospraying and chemical activation. According to SEM and EDX, results showed that a significantly different Al/Si atomic percentage was obtained by chemical activation compared to the electrospraying method. Additionally, the surface roughness (Sa) values significantly improved following the surface modification procedure. The surface roughness of PP/Zeo membranes modified with 5% (w/v) zeolite using the chemical activation method was 0.189 μm, compared to 0.143 μm for pure PP. This work presents a facile and effective preparation method to be used as filter for membrane filtration applications.Highlights Polyprophylene (PP) and zeolite (Zeo) were combined for effective filtration. PP or PP/Zeo fiber membranes were prepared by melt‐electrospinning. The surface was modified comparatively using electrospraying and Garcia methods. SEM analyses indicated that the surface was coated with zeolite particles.

Phase tailoring of silver oxide thin films for improved antimicrobial activity

This paper reports on routes to control the silver oxide phase and morphology in thin films to enhance their antimicrobial efficacy. The Ag:O atomic ratio was tailored during the pulsed laser deposition process by adjusting the O2 environment, and thus, a wide range of silver oxide phases ranging from Ag to AgxO was achieved. Simultaneously, the morphology was controlled from island-like (Volmer–Weber) formations to nanoparticle arrays, ultimately culminating in cauliflower-like dendrite structures. Through this synergistic approach, enhancing the oxygen content while expanding the active surface area yielded optimal enhancement of the antimicrobial properties. Remarkably, films deposited at elevated O2 pressures exhibited heightened inhibitory effects against bacterial biofilms, with films featuring nanoparticle morphology demonstrating notable antistaphylococcal efficacy.

“Coordination caps” of graded electron-donor capacity

Abstract An efficient synthesis of the novel {6-[1,1-di(pyridin-2-yl)ethyl]pyridine-2-yl}2-methyl-1,3-propanediamine (2) is reported, as well as a reliable large-scale synthesis (of the order of 100 g) of previously known 2,2’-[1-(6-chloropyridin-2-yl)ethane-1,1-diyl]dipyridine (4); the latter is the starting material for the preparation of the former, as well as a multitude of other polypodal polyamine/polyimine ligands. Both materials, as well as the intermediates in their multi-step syntheses, have been fully characterised. Ligand 2, in conjunction with ligands 2,2’-(pyridine-2,6-diyl)bis(2-methylpropane-1,3-diamine) (1) and 2,6-bis(1,1-di(pyridin-2-yl)ethyl)pyridine (3), establishes a series of tetrapodal pentadentate N5 ligands L of like scaffold, and thus coordination geometry, but graded primary amine/imine donor atom ratios. The iron(II) complexes [Fe(L)NCCH3](OTf)2 (L = 1: A; L = 2: B; L = 3: C; OTf = triflate) have been prepared and fully characterised, including X-ray single-crystal structure analyses. The metal-centred one-electron oxidation/reduction potential (FeII/FeIII) depends sensitively on the electron donor capacity of the capping ligand used, as demonstrated by cyclic voltammetry. Whereas the acetonitrile ligand in A and C is readily exchanged for a methanol ligand in methanol solution, the resulting complexes showing variable-temperature spin crossover (SCO) in solution, B has been found to be inert to this type of ligand exchange.