Properties Of Cu Research Articles

Machine learning potential for the Cu-W system

Combining the excellent thermal and electrical properties of Cu with the high abrasion resistance and thermal stability of W, Cu-W nanoparticle-reinforced metal matrix composites and nano-multilayers are finding applications as brazing fillers and shielding material for plasma and radiation. Due to the large lattice mismatch between fcc Cu and bcc W, these systems have complex interfaces that are beyond the scales suitable for methods, thus motivating the development of chemically accurate interatomic potentials. Here, a neural network potential (NNP) for Cu-W is developed within the Behler-Parrinello framework using a curated training dataset that captures metallurgically relevant local atomic environments. The Cu-W NNP accurately predicts (i) the metallurgical properties (elasticity, stacking faults, dislocations, thermodynamic behavior) in elemental Cu and W, (ii) energies and structures of Cu-W intermetallics and solid solutions, and (iii) a range of fcc Cu/bcc W interfaces, and exhibits physically reasonable behavior for solid W/liquid Cu systems. As will be demonstrated in forthcoming work, this near accurate NNP can be applied to understand complex phenomena involving interface-driven processes and properties in Cu-W composites. Published by the American Physical Society 2024

The Effect of Na2O/B2O3 Composition Ratio on the Structure and Properties of Cu+ Doped Luminescent Glass

The Effect of Na2O/B2O3 Composition Ratio on the Structure and Properties of Cu+ Doped Luminescent Glass

Preparation and properties of Cu2MgSnS4 thin films and fabrication of heterojunction devices

Abstract Copper based chalcogenides have garnered growing importance in the area of thin film photovoltaics. Cu2MgSnS4 (CMTS) is one of the newest materials in this family of materials. It is a p-type material which find multiple applications in the field of photovoltaics. Cu2MgSnS4 thin films were deposited onto soda lime glass substrates using automated vacuum spray pyrolysis technique at a substrate temperature of 300 °C and annealed at different temperatures from 300 °C to 375 °C in steps of 25°C. The structural, elemental, morphological, optical, and electrical properties of the material were studied. X-Ray Diffraction studies showed that annealing eliminates impurity phases and improves crystallinity. Field Emission Scanning Electron Microscopy studies showed improved grain size and uniform deposition of the films. The energy bandgap of the as-prepared film is 2.02 eV and that of annealed films are around 2.5 eV. Hall measurements show that the material exhibit p-type conductivity with high value of conductivity, mobility and bulk concentration. Heterojunction devices were fabricated with chemical bath deposited CdS as a buffer layer and spray deposited Aluminium doped Zinc Oxide (Al:ZnO) as n-layer. Silver contacts were placed as electrodes over the top layer. The fabricated device architecture is <FTO/AZO/CdS/CMTS/Ag>. The junction parameters including rectification ratio, knee voltage, series resistance and Ideality factor of all the devices are calculated. The device annealed at 375 °C showed an ideality factor of 2.23, which is the best among all the fabricated devices.

A collagenase-decorated Cu-based nanotheranostics: remodeling extracellular matrix for optimizing cuproptosis and MRI in pancreatic ductal adenocarcinoma

Pancreatic ductal adenocarcinoma (PDAC), characterized by a dense extracellular matrix (ECM), presents significant therapeutic challenges due to its poor prognosis and high resistance to chemotherapy. Current chemodrugs and diagnostic agents largely fail to cross the barrier posed by the ECM, which severely limits the PDAC theranostics. This study introduces a novel theranostic strategy using thioether-hybridized hollow mesoporous organosilica nanoparticles (dsMNs) for the co-delivery of copper (Cu) and disulfiram (DSF), aiming to induce cuproptosis in PDAC cells. Our approach leverages the ECM-degrading enzyme collagenase, integrated with dsMNs, to enhance drug penetration by reducing matrix stiffness. Furthermore, the innovative use of a pancreatic cancer cell membrane coating on the nanoparticles enhances tumor targeting and stability (dsMCu-D@M-Co). The multifunctional platform not only facilitates deep drug penetration and triggers cuproptosis effectively but also utilizes the inherent properties of Cu to serve as a T1-weighted magnetic resonance imaging (MRI) contrast agent. In vitro and in vivo assessments demonstrate significant tumor size reduction in PDAC-bearing mice, highlighting the dual functionality of our platform in improving therapeutic efficacy and diagnostic precision. This integrated strategy represents a significant advancement in the management of PDAC, offering a promising new direction for overcoming one of the most lethal cancers.Graphical

Impact of oxygen vacancies on the structural, electronic, and optical properties of Cu<i>2</i>O and nitrogen-doped Cu<sub>2</sub>O for optoelectronic applications: a first-principles study

This study utilizes Density Functional Theory (DFT) within the Quantum ESPRESSO framework to explore the effects of oxygen vacancies and nitrogen doping on the electronic structure and optical properties of cuprous oxide (Cu2O). Pristine Cu2O, an intrinsic p-type semiconductor, typically exhibits a direct band gap. Introducing an oxygen vacancy in the absence of a dopant broadens the band structure, leading to both direct and indirect band gap characteristics. In contrast, nitrogen doping transforms the band gap into a direct one, significantly reducing it from 1.97 eV to 1.09 eV, which deviates from previous findings due to potential variations in the initial state of the Cu2O host crystal. Furthermore, spin-polarization effects indicate spin-dependent behaviour within the material. The study also examines the absorption properties of pristine, defective, and nitrogen-doped Cu2O systems using the complex dielectric function. The results show distinct absorption peaks and transitions, with nitrogen-doped Cu2O exhibiting strong absorption in the visible light range, underscoring its potential for solar cell applications.

Geochemical Characteristics and Environmental Risks of Cu in the Soil of A Sloping Vineyard (Phu Tho Province, Vietnam)

In the vineyards, the intensive use of cupric fungicides and fertilizers has resulted in Cu enrichment in the soils. Specifically, in sloping vineyards, the mobility of Cu can contribute to intensify the environmental risks. The research on geochemical characteristics of Cu is a key solution to explore the distribution of Cu in different geochemical fractions and understand the mobility and toxicity of this element in the environment. In this study, we aim to investigate the geochemical properties of Cu in the vineyard topsoil (0-20 cm) and subsoil (20-40-60 cm), using the improved three-step sequential extraction procedure developed by the Commission of the European Communities Bureau of Reference (BCR). In addition, the environmental risk is calculated by the environmental risk code (RAC) based on the percentage of Cu in the acid-soluble fraction. The results reveal that the mobility of Cu in the acid-soluble fraction (F1) and reducible fraction (Cu associated with the iron and manganese oxyhydroxides) (F2) tends to decrease with increasing soil depth. The major portion of Cu mostly exists in the strong bond with silicate clays (F4), accounting for 84% of total Cu content on average. Contrarily, the minor propotion of Cu associates with soil organic matter (F3) (3% on average). On the other hand, the content and proportion of Cu in the soil fractions are largerly influenced by basic soil properties (organic matter contents and fine soil particles). In addition, under the impact of soil erosion, higher percentages of F1 and F2 fractions of Cu are observed in the surface soil layers at the top of the hill compared to those at the backslope of the hill. The mean calculated RAC of 10.66%, 5.76%, and 5.38% for the 0-20 cm, 20-40 cm, and 40-60 cm soil layers, respectively, demonstrate a low risk to medium environmental risk level in the studied vineyard. Although an overall low risk level is observed for Cu in the studied vineyard soil, the deposition of Cu originating from repeated Cu-based pesticides and erosion is of particular concern in the vineyard soils.

Atomic cluster expansion interatomic potential for defects and thermodynamics of Cu–W system

The unique properties exhibited in immiscible metals, such as excellent strength, hardness, and radiation-damage tolerance, have stimulated the interest of many researchers. As a typical immiscible metal system, the Cu–W nano-multilayers combine the plasticity of copper and the strength of tungsten, making it a suitable candidate for applications in aerospace, nuclear fusion engineering, and electronic packaging, etc. To understand the atomistic origin of the defects (e.g., vacancies, free surfaces, grain boundaries, and stacking faults and thermodynamical properties), we developed an accurate machine learning interatomic potential for Cu–W based on the atomic cluster expansion (ACE) method. The Cu–W ACE potential can faithfully reproduce the fundamental properties of Cu and W predicted by density functional theory (DFT) calculations. Moreover, the thermodynamical properties, such as the melting point, coefficient of thermal expansion, diffusion coefficient, and equation of the state curve of the Cu–W solid solution, are calculated and compared against DFT and experiments. Monte Carlo molecular dynamics simulations performed with the Cu–W ACE potential predict the experimentally observed phase separation and uphill diffusion phenomena. Our findings not only provide an accurate ACE potential for describing the Cu–W immiscible system but also shed light on understanding the atomistic mechanism during the Cu–W nano-multilayers formation process.

Effect of pre-aging on mechanical reinforcement of the Cu–Fe–Nb composites

Pre-aging treatment was demonstrated to significantly enhance the mechanical properties of Cu–10Fe–1Nb (wt.%) composites. Specifically, after rolling and aging at 400 °C for 8 h, the microhardness, tensile strength, and elongation of the pre-aged samples reached 163 HV, 559 MPa, and 11.2%, respectively. The refinement of Fe-rich phases in pre-aged samples was primarily attributed to the increased shear strain between the Fe-rich phases and the matrix, which was driven by the precipitation-strengthening effect induced by pre-aging. Additionally, the matrix of the pre-aged samples suffered significant refinement as dynamic recovery and recrystallization of the matrix were suppressed during the rolling process, forming a high-density dislocation structure that greatly enhances the work-hardening effect. The main contribution to strength improvement in the Cu–10Fe–1Nb composites was identified as precipitation strengthening, refinement strengthening, and work hardening. Moreover, compared with the sample without pre-aging treatment, the refinement strengthening and work hardening effects of pre-aged samples exhibited substantial improvements, with increment of 49 MPa and 21 MPa, respectively.

Microstructure and Properties of Cu – Cr – Zr Alloys After Plastic Deformation and Aging

Microstructure and Properties of Cu – Cr – Zr Alloys After Plastic Deformation and Aging

Mechanical and Electrical Conductivity Properties of Graphene/Cu Interfaces: A Theoretical Insight.

For graphene/copper (Gr/Cu) composites, achieving high-quality interfaces between Gr and Cu (strong interfacial bonding strength and excellent electron transport performance) is crucial for enabling their widespread applications in electronic devices. This study employs first-principles calculations and the nonequilibrium Green's function method to systematically investigate the mechanical and electrical conductivity properties of Cu(111)/Gr/Cu(111) interfaces with various stacking sequences and different forms of Gr. For these interface systems, the binding energy, separation work, charge transfer, and electrical conductivity across the interface were obtained. The results show that the top-fcc interface exhibits superior interfacial properties, characterized by relatively high binding energy (-3.00 eV/C atom) and separation work (≥0.78 J/m2), a small interfacial distance (2.85 Å), and enhanced electron transport capacity (2.12 G0/nm2). A bilayer form of Gr significantly reduces electronic conductance across the Gr/Cu interface by nearly 2.46 orders of magnitude. Furthermore, point defects in Gr, especially single-vacancy defects, disrupt the traditional trade-offs between mechanical and electrical performance, simultaneously enhancing mechanical performance by 7.50-124.36% and electrical performance by 33.02%. Additionally, stress mechanisms have been proposed to further enhance the interfacial electrical conductivity of Gr/Cu composites. The present study provides a theoretical basis for exploring the engineering applications of Gr/Cu composite materials.

Effect of Ga Variation on the Bulk and Grain‐Boundary Properties of Cu(In,Ga)Se2 Absorbers in Thin‐Film Solar Cells and Their Impacts on Open‐Circuit Voltage Losses

ABSTRACTPolycrystalline widegap Cu(In,Ga)Se2 (CIGSe) absorbers for top cells in photovoltaic tandem devices can be synthesized via [Ga]/([Ga] + [In]) (GGI) ratios of > 0.5. However, the power conversion efficiencies of such high‐GGI devices are smaller than those of the record cells with GGI < 0.5. In the present work, the effects of the GGI ratio on various CIGSe material properties were studied and correlated with the radiative and nonradiative open‐circuit voltage (VOC) deficits of the thin‐film solar cells. Average grain sizes, grain boundary (GB) recombination velocities, fluctuations in luminescence energy distribution, barrier heights at GBs, effective electron lifetimes, and Urbach energies were investigated in five solar cells with GGI ratios from 0.13 to 0.83. It was found that the GGI variation affects GB recombination velocities, fluctuations in spatial luminescence distributions, the average grain size, the electron lifetime, and the Urbach energy. In contrast, the detected ranges of barrier heights at GBs are independent of the GGI ratio. Mainly Ga/In gradients give rise to substantial radiative VOC losses in all solar cells. Nonradiative VOC deficits are dominant especially for solar cells with GGI > 0.5, which can be attributed to low bulk lifetimes and enhanced recombination at GBs in CIGSe absorbers in this compositional range.

Thermodynamic, structural and surface properties of Cu–Zr liquid alloy at different temperatures: A theoretical approach

Thermodynamic, structural and surface properties of Cu–Zr liquid alloy at different temperatures: A theoretical approach

Improving comprehensive properties of Cu−11.9Al−2.5Mn shape memory alloy by adding multi-layer graphene carried by Cu51Zr14 inoculant particles

In order to improve the comprehensive properties of the Cu−11.9Al−2.5Mn shape memory alloy (SMA), multilayer graphene (MLG) carried by Cu51Zr14 inoculant particles was incorporated and dispersed into this alloy through preparing the preform of the cold-pressed MLG−Cu51Zr14 composite powders. In the resultant novel MLG/Cu−Al−Mn composites, MLG in fragmented or flocculent form has a good bonding with the Cu−Al−Mn matrix. MLG can prevent the coarsening of grains of the Cu−Al−Mn SMA and cause thermal mismatch dislocations near the MLG/Cu−Al−Mn interfaces. The damping and mechanical properties of the MLG/Cu−Al−Mn composites are significantly improved. When the content of MLG reaches 0.2 wt.%, the highest room temperature damping of 0.0558, tensile strength of 801.5 MPa, elongation of 10.8%, and hardness of HV 308 can be obtained. On the basis of in-depth observation of microstructures, combined with the theory of internal friction and strengthening and toughening theories of metals, the relevant mechanisms are discussed.

Engineering Cu–Ce-a nanozymes: Revolutionary alloy nanomaterials mimicking cytochrome c oxidase for ultra-sensitive cytochrome c detection

The design of synthetic analogs of cytochrome c oxidase (CcO) is a formidable task due to its intricate structure encompassing multiple metal prosthetic sites and protein subunits. In recent years, artificial enzymes based on alloy nanomaterials have garnered significant attention due to the alloy design approach holds promise for the effective tuning of the properties of metal catalysts. In this study, we present copper-cerium alloy nanozymes (Cu–Ce-a NEs), where Cu mimics the active site of CcO, while Ce endows the alloy phase and enhances the capacity to catalyze the oxidation to cytochrome c (Cyt c). Cu–Ce-a NEs functionally mimics CcO, the terminal enzyme in the respiratory electron transport chain (ETC), by catalyzing the four-electron reduction of dioxygen to water. Utilizing the CcO-like properties of Cu–Ce-a NEs, we successfully implemented the electrochemical detection of Cyt c. The Cu–Ce-a NEs based electrochemical sensor revealed a favorable linear range spanning from 2 to 20 μM Cyt c, with a detection limit (LOD) of 2 μM. This method demonstrates high accuracy in Cyt c quantitation in pharmaceuticals, with results closely aligning with the actual concentrations. This finding not only offers new perspectives in the design of enzyme analogs, but also underscores the potential of this method for clinical Cyt c detection, highlighting its significance in biomedical research and diagnostics.

Thermal Properties of Cu–Al–Ge Alloy PCM for Improving Thermal Energy Storage of Current CSP

Metallic phase change material was proposed and examined at melting/eutectic temperatures less than 600 °C for latent heat storage in concentrated solar power. The PCM alloy can potentially charge/discharge thermal energy as a sensible/latent heat at the temperature range of 414-527 °C. The working temperatures of PCM alloy are in operation temperatures of current molten-salt based CSP plant. In this study, thermal response testing of PCM alloy and sensible/latent storage unit that PCM alloy was loaded in a ceramic honeycomb were prepared in a laboratory scale. The thermal charging/discharging performance of PCM alloy and sensible/latent storage unit were experimentally examined and compared. The storage unit provided thermal release/absorption behaviour at close to temperatures of the thermodynamic equilibrium state.

Fluorescent cellulose nanofibrils hydrogels for sensitive detection and efficient adsorption of Cu2+ and Cr6+

Increasing chromium and copper pollution poses a significant threat to the global environment and human health. It is crucial to detect and remove Cu (II) and Cr (VI) from water. Cellulose nanofibrils (CNF)-based hydrogels were a natural, abundant, and biocompatible material that has attracted great attention for bio adsorption applications. In this work, a new fluorescent CNF-based hydrogel (PAA-CNF-W) was prepared for the high-efficiency adsorption and sensitive detection of Cu (II) and Cr (VI). CNF was introduced as a natural backbone to construct a three-dimensional porous structure, which increased the specific surface area and provided additional active sites, exhibiting excellent adsorption properties for Cu (II) (159.24 mg/g) and Cr (VI) (173.87 mg/g). Moreover, the synthesized dansyl chloride derivatives with fluorescent properties were introduced to the hydrogel and formed chelates with the metals leading to fluorescence quenching. PAA-CNF-W hydrogels showed high sensitivity to the detection limit (LOD) of Cu (II) (28.70 mg/L) and Cr (VI) (1.45 mg/L). The kinetic study revealed that pseudo-second order kinetics was the best-fitting model. The Langmuir isotherm was the best adjustment model. The study provides a new idea for efficient detection and removal of Cu (II) and Cr (VI) from wastewater by cellulose materials.

Redox Concomitant Formation Method for Fabrication of Cu(I)-MOF/Polymer Composites with Antifouling Properties.

Marine biofouling, which is one of the technical challenges hindering the growth of the marine economy, has been controlled using cuprous oxide (Cu2O) nanoparticles due to the exceptional antifouling properties of Cu(I) ions. However, Cu2O nanoparticles have encountered bottlenecks due to explosive releases of Cu+ ions, high toxicity at elevated doses, and long-term instability. Here, we present a novel method called Redox Concomitant Formation (RCF) for fabricating a hierarchical Cu(I) metal-organic framework polypyrrole (Cu(I)-MOF/PPy) composite. This method enables in-situ phase transition via successive redox reactions that change the chemical valence state and coordination mode of Cu(II)-MOF, resulting in a new structure of Cu(I)-MOF while creating a PPy layer surrounded by the hierarchical structure. Owing to the steady release of Cu+ ions from the Cu(I) sites and photothermal properties of PPy, Cu(I)-MOF/PPy exhibits superior and broad-spectrum resistance to marine bacteria, algae, and surface-adhered biofilms in complex biological environments, as well as long-term stability, resulting in 100% eradication efficiency under solar-driven heating. Mechanistic insights into successive structural redox reactions and formation using the RCF method are provided in detail, enabling the fabrication of novel MOFs with the desired composition and structure for a wide range of potential applications.

Redox Concomitant Formation Method for Fabrication of Cu(I)−MOF/Polymer Composites with Antifouling Properties

AbstractMarine biofouling, which is one of the technical challenges hindering the growth of the marine economy, has been controlled using cuprous oxide (Cu2O) nanoparticles due to the exceptional antifouling properties of Cu(I) ions. However, Cu2O nanoparticles have encountered bottlenecks due to explosive releases of Cu+ ions, high toxicity at elevated doses, and long‐term instability. Here, we present a novel method called Redox Concomitant Formation (RCF) for fabricating a hierarchical Cu(I) metal–organic framework polypyrrole (Cu(I)−MOF/PPy) composite. This method enables in situ phase transition via successive redox reactions that change the chemical valence state and coordination mode of Cu(II)−MOF, resulting in a new structure of Cu(I)−MOF while creating a PPy layer surrounded by the hierarchical structure. Owing to the steady release of Cu+ ions from the Cu(I) sites and photothermal properties of PPy, Cu(I)−MOF/PPy exhibits superior and broad‐spectrum resistance to marine bacteria, algae, and surface‐adhered biofilms in complex biological environments, as well as long‐term stability, resulting in 100 % eradication efficiency under solar‐driven heating. Mechanistic insights into successive structural redox reactions and formation using the RCF method are provided in detail, enabling the fabrication of novel MOFs with the desired composition and structure for a wide range of potential applications.

Effects of B Addition on Microstructure Evolution and Efficient Hydrogen Evolution of Self‐Supported Cu–Fe–P Immiscible Alloy

Herein, the effect of B elements on the microstructure and catalytic properties of Cu–31.5Fe–4.5P immiscible alloy is systematically investigated. After microstructure characterizations, it is found that B elements are mainly concentrated in FexP (Fe2P, Fe3P) particles, which affect the Marangoni motion of the particles. With the concentration of B content increasing to 0.75%, the diameter size of the second‐phase particles in the alloys is first refined and then coarsened, in which the alloy with B content of 0.25% has the finest particle size and the proportion of second‐phase particles with sizes ranging from 1 to 10 μm reaches 97%. The electrochemical characterization of dealloyed specimens shows that the overpotential of Cu–Fe–P alloys containing 0.25% B reaches 193 mV at a current density of 10 mA cm−2 in 0.5 m H2SO4 solution. The excellent catalytic performance might be attributed to the increase in the obviously specific surface area of Fe2P and Fe3P particles and the significant increase in the electron transfer.

STUDY OF COPPER COMPLEXES [Cu(LCF3)2] AND [Cu(Lcur)2]H2O AS RADIOPROTECTIVE COMPOUNDS

One of the first and direct signs of the impact of ionizing radiation (IR) on a cell is the destabilization of chromosomes. Radiation-induced damage to the karyotype is an important indicator both for biological indication of the severity of radiation injuries and for predicting the development of long-term adverse effects of IR. The search for new, effective radioprotective compounds is a priority task of modern radiobiology. In this area, metal-based compounds with high antioxidant activity are of particular interest. The purpose of this work is to determine the possible radioprotective properties of Cu(II) complexes, [Сu(LCF3)2] and [Cu(Lcur)2]H2O, supported by the anions of the β-diketone ligands 1,1,1,5,5,5-hexafluoro-2,4-pentanedione (HLCF3) and 1,7-bis(4-hydroxy-3-methoxyphenyl)-1,6-heptadiene-3,5-dione or curcumin (HLcur). In this research work we determined survival, life expectancy and cytogenetic parameters: mitotic index, chromosome aberrations and % of polyploid cells in the bone marrow cells of the femur (count in 1000 cells in each preparation). Group I included intact animals; Group II consisted of animals exposed to the radioisotope technetium; Group III consisted of animals that were intraperitoneally injected with copper complex [Cu(LCF3)2] at a dose of 50 mg/kg in a volume of 2 mL one hour before the administration of the Tc isotope (“irradiation + copper compound [Cu(LCF3)2]); Group IV included animals that received the compound [Cu(Lcur)2]H2O before irradiation. The groups with the injection of [Cu(LCF3)2] complex had the highest survival. In terms of chromosomal aberrations and number of polyploid cells, as indicators, a significant difference was found in those irradiated compared with the “irradiation + [Cu(LCF3)2]” group (both after 15 and after 30 days), which indicates the radioprotective property of the compound. In terms of the mitotic index, a tendency towards normalization was noted after 15 days and a significant difference between Groups 2 and 3 by the end of the study (after 30 days), which also proves the beneficial effect of this compound. Analysis of survival and changes in cytogenetic parameters multiregression analysis using both complexes confirms the greatest efficiency of the [Cu(LCF3)2] complex with respect to [Cu(Lcur)2]H2O, because when using [Cu(Lcur)2]H2O in Group IV and comparing it with “pure irradiation” only a tendency toward normalization of cytogenetic parameters was observed. Multiregression analysis of cytogenetic parameters also confirmed the highest efficiency of the [Cu(LCF3)2] compound in comparison with [Cu(Lcur)2]H2O. The results of the research indicate the need to continue work in the direction of searching for agents that have a therapeutic effect in radiation injuries.