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This article investigates the impact of metal-organic frameworks (MOFs) on the performance and stability of perovskite solar cells (PSCs), specifically focusing on the type of metal and the morphology of the MOF. Two types of MOFs, copper-benzene-1,3,5-tricarboxylate (Cu-BTC MOF) with spherical morphology and cobalt-benzene-1,3,5-tricarboxylate (Co-BTC MOF) with rod morphology, are synthesized and spin-coated on TiO2 substrates to form FTO/TiO2/MOF/CH3NH3PbI3/C-paste PSCs. The morphology and size of the MOFs are characterized by scanning electron microscopy (SEM), and the crystallinity and residual PbI2 of the perovskite films are analyzed by X-ray diffraction (XRD). The results show that the Co-BTC MOF PSC exhibits the highest power conversion efficiency (PCE) of 10.4% and the best stability, retaining 82% of its initial PCE after 264 h of storage in ambient air. The improved performance and stability are attributed to the enhanced crystallinity and reduced residual PbI2 of the perovskite film after Co-BTC MOF modification. The paper showcases the immense potential of MOF-based interlayers to revolutionize PSC technology, offering a path toward next-generation solar cells with enhanced performance and longevity. [ABSTRACT FROM AUTHOR]

In this paper, copper coated carbon nanotubes (CNTs) was synthesized by decomposition of Cu(II) acetylacetonate (Cu(acac)2) in hydrogen atmosphere at 300 °C. The thickness of the copper coating was in nanoscale according to scanning electron microscopy (SEM) and transmission electron microscopy (TEM) images, and Raman spectra indicated that certain intermediate bonds were formed between copper and the template CNTs. The crystalline structure of copper and its growth orientation were determined by X-ray diffraction (XRD) and selected area electron diffraction (SAED). The copper coating on CNTs had a face-centered cubic structure and its growth orientation was parallel to $$ (\bar 111) $$ planes. The method developed in this paper had the advantages of simplicity in both process control and experiment equipments, so that it might provide a possibility of large-scale production. [ABSTRACT FROM AUTHOR]

In this paper, the single-step solvothermal method was proposed to grow directly Cu2ZnSn (SxSe1−x)4 (CZTSSe) thin films on FTO substrates. The composition ‘x’ was varied by changing the molar ratios of thiourea to selenourea in the precursor solutions. The effects of the molar ratios of thiourea to selenourea on the structure, morphology and optical properties of CZTSSe thin films were investigated by X-ray diffraction, Raman spectroscopy, scanning electronic microscopy, energy dispersive spectrometry and UV-Vis spectrophotometry. The results indicated that CZTSSe thin films are composed of a large number of uniform sphere-like particles, and the diameter of particles varies from 600 to 280 nm when the molar ratios is changed from 1 to 0. The major XRD diffraction peaks shift towards lower diffraction angles, the Raman peak position of A1 mode of CZTSSe thin films moves consecutively towards the lower frequency due to the S replacement by Se. CZTS and CZTSe thin films are single kesterite structure, however, CZTSSe thin films are mixture structure of kesterite and wurtzite. By varying the molar ratios of thiourea to selenourea in the precursor solution, the atom ratios of S/Se in CZTSSe NCs thin films can be well controlled over the whole range, resulting in tunable optical band gap from 1.54 to 1.38 eV. [ABSTRACT FROM AUTHOR]

A bonding method utilizing redox reactions of metallic oxide microparticles achieves metal-to-metal bonding in air, which can be alternative to lead-rich high-melting point solder. However, it is known that the degree of the reduction of metallic oxide microparticles have an influence on the joint strength using this bonding method. In this paper, the reduction behavior of CuO paste and its effect on Cu-to-Cu joints were investigated through simultaneous microstructure-related x-ray diffraction and differential scanning calorimetry measurements. The CuO microparticles in the paste were gradually reduced to submicron Cu2O particles at 210-250°C. Subsequently, Cu nanoparticles were generated instantaneously at 300-315°C. There was a marked difference in the strengths of the joints formed at 300°C and 350°C. Thus, the Cu nanoparticles play a critical role in sintering-based bonding using CuO paste. Furthermore, once the Cu nanoparticles have formed, the joint strength increases with higher bonding temperature (from 350°C to 500°C) and pressure (5-15 MPa), which can exceed the strength of Pb-5Sn solder at higher temperature and pressure. [ABSTRACT FROM AUTHOR]

This paper reports colossal dielectric constant (10 order) in the low-frequency region for sintered bulk ceramics of CaCuTiO (CCTO) super-capacitor. X-ray diffraction of sintered CCTO sample confirms cubic structure with Im3 space group. Analysis of micrograph on the parallel surfaces of the sintered solid exhibits the homogeneous distribution of grains and grain boundaries on the surface of the pellet. Detail study of Raman scattering data suggests the appearance of polarizable relaxation mode. Studies of capacitive and resistive characteristics of the material in a wide range of frequency of applied electric field and temperature shows that dielectric permittivity, energy loss, impedance, electric modulus and electrical conduction of the material are strongly affected by experimental conditions (frequency and temperature). A good correlation between above electrical parameters (resistance, capacitance, conductance, etc.) and the contents of microstructure (grains and grain boundary) of the material are established. It is expected that use of nano-size TiO and CuO powders in the initial stage with micron size powder of CaCO can help for rapid solid state reaction at microscopic level which is likely to be responsible for high dielectric constant of the material. Present findings suggest that CCTO can be considered as a potential candidate for super-capacitor devices. [ABSTRACT FROM AUTHOR]

Structure of metallic glasses fascinates as the generic amorphous structural template for ubiquitous systems. Its specification necessitates determination of the complete hierarchical structure, starting from short-range-order (SRO) → medium-range-order (MRO) → bulk structure and free volume (FV) distribution. This link has largely remained elusive since previous investigations adopted one-technique-at-a-time approach, focusing on limited aspects of any one domain. Reconstruction of structure from experimental data inversion is non-unique for many of these techniques. As a result, complete and precise structural understanding of glass has not emerged yet. In this work, we demonstrate the first experimental pathway for reconstruction of the integrated structure, for Zr 67 Ni 33 and Zr 52 Ti 6 Al 10 Cu 18 Ni 14 glasses. Our strategy engages diverse (× 7) multi-scale techniques [XAFS, 3D-APT, ABED/NBED, FEM, XRD, PAS, FHREM] on the same glass. This strategy complemented mutual limitations of techniques and corroborated common parameters to generate complete, self-consistent and precise parameters. Further, MRO domain size and inter-void separation were correlated to identify the presence of FV at MRO boundaries. This enabled the first experimental reconstruction of hierarchical subset: SRO → MRO → FV → bulk structure. The first ever image of intermediate region between MRO domains emerged from this link. We clarify that determination of all subsets is not our objective; the essence and novelty of this work lies in directing the pathway towards finite solution, in the most logical and unambiguous way. [ABSTRACT FROM AUTHOR]

This paper describes the pure and copper doped SnO nanocrystalline thin films with large specific surface areas fabricated on a desired substrate using a simple chemical bath deposition technique. The as-deposited films were annealed at 500 °C for 2 h in ambient atmosphere in order to improve the crystallinity and structural perfection. The influence of Cu doping on structural, optical, and surface topography of the thin films was studied by X-ray diffraction (XRD), Raman spectra, UV-Vis spectra, photoluminescence, and atomic force micrograph images. The XRD measurements showed that films had a tetragonal rutile type structure with P 42/mnm symmetry and the results were good in agreement with the standard JCPDS data (card no: 41-1445). The surface roughness and porosity has been found to decrease with the increase of the dopant concentration as investigated by atomic force microscopy. The characteristic Raman peaks observed at 325, 466, 672 and 745 cm were respectively revealed infrared active (E), Raman active (E), (A) and (B) vibration modes of pure tetragonal rutile SnO structure. The optical band gap energy of pure SnO has been found to be in the range of 3.68 eV and it is shifted to 3.32 eV for 10 wt% Cu doping. The photocatalytic activities of the films were evaluated by the degradation of methylene blue rhodamine B in an aqueous solution under ultraviolet light irradiation. The photocatalytic activity and reusability of Cu (10 wt%) doped SnO film was much higher than that of the pure SnO. [ABSTRACT FROM AUTHOR]

In magnetron sputtering, with the simultaneous deposition of SmCo and copper, it is possible for tailoring the coercive field of SmCoCu thin films. Microstructural analysis pointed out that nanocrystalline 2:17 rhombohedral phase with diameter 10–100 nm was obtained, and coercivities in the range between 3 and 8.5 kOe. These characteristics are suitable for magnetic recording. The coercivity mechanisms are discussed. The initial magnetization curve, measured in thermally demagnetized samples, is used to discuss the coercivity mechanisms. A spring effect in the samples is observed. The spring effect is due to reversible rotation of magnetization and indicates that the coercivity mechanism is nucleation or coherent rotation of single domain size nanoscale grains. Structural data refined with X-ray diffraction Rietveld analysis for Sm2(Co,Cu)17 rhombohedral phase, Sm(Co,Cu)5 phase and cubic oxide Sm2O3 phase are provided. [ABSTRACT FROM AUTHOR]

Electro-discharge machining (EDM) is a widely accepted nontraditional machining process used mostly for machining materials difficult to machine by conventional shearing process. Surface modification by powder metallurgy sintered tools is an uncommon aspect of EDM. Of late, it is being explored by many researchers. In the present paper, attempts have been made to model the surface modification phenomenon by EDM with artificial neural networks. Two output measures, material transfer rate and average layer thickness, have been correlated with different process parameters and presented in the form of plots. The predicted results are matching well with the experimental results. [ABSTRACT FROM AUTHOR]

Correct identification of pigments and all accompanying phases found in colour layers of historical paintings are relevant for searching their origin and pigment preparation pathways and for specification of their further degradation processes. We successfully applied the analytical route combining non-destructive in situ X-ray fluorescence analyses with subsequent laboratory investigation of micro-samples by optical microscopy, scanning electron microscopy/energy-dispersive spectroscopy and X-ray powder micro-diffraction (micro-XRD) to obtain efficiently all the data relevant for mineralogical interpretations of the copper pigments origin. Cu salts (carbonates, chlorides, sulphates, etc.) used as pigments exist in a range of polymorphs with similar or identical composition. The efficiency of the micro-XRD for direct identification of such crystal phases present in micro-samples of colour layers was demonstrated in the presented paper. A new, until now unpublished, type of copper pigment—cumengeite, Pb21Cu20Cl42(OH)40—used as a blue pigment on a sacral wall painting in the Czech Republic was found by means of micro-XRD. Furthermore, azurite, malachite, paratacamite, atacamite and posnjakite were identified in fragments of colour layers of selected Gothic wall paintings. We found Cu–Zn arsenates indicating the natural origin of azurite and malachite; artificial malachite was distinguishable according to its typical spherulitic crystals. The corrosion of blue azurite to green basic Cu chloride was clearly evidenced on some places exposed to the action of salts and moisture—in a good agreement with the results of laboratory experiments, which also show that oxalic acid accelerates the corrosion of Cu pigments. [Figure not available: see fulltext.] [ABSTRACT FROM AUTHOR]

One of the major sources of contamination during mechanical milling/alloying is from the surface erosion of the container and the grinding medium. This can either be prevented by using grinding medium and container of same material of the milled material or by adding a coating of the milled material on them. The paper describes the observations made during a mechano-chemical reaction, being used for coating the balls and vials in a planetary ball mill. Visual observation, XRD, optical micrography and EDS analysis were used to understand the progress of the reaction. Copper was successfully coated on the steel balls and vials. The method can easily be adopted in daily production purposes, prior to mechanical milling of a Cu-based powder for prevention of Fe contamination. [ABSTRACT FROM AUTHOR]

The formation of the gold layer in mercury gilding occurs through the heating a gold amalgam. As a result, the formation mechanism and technical characteristics of gilded products are closely related to the temperature at which they are heated. In this study, XRD and XPS analysis of a copper-gilded coronet from the Sui or Tang dynasties revealed that Au3Cu was one of the main phases of the gold layer. Therefore, base on the thermodynamic stability of ordered phases like Au3Cu, the estimated heating temperature for this copper-gilded coronet ranged from 240 to 285 ℃. Furthermore, SEM–EDS analysis of the cross-sectional concentration distribution of Cu indicated that the diffusion distance of Cu during heating did not exceed 2 μm. At 240–285 ℃, Cu diffused along the defects of the gold layer, and the diffusion process followed Fick's second law. Previous research has indicated that the defect path diffusion coefficient of Cu is on the order of 10–12 cm2/s, and the heating time of the gilding process is typically considered to be 15 min. Using the diffusion equation, the calculated diffusion distance of Cu aligned with the diffusion behavior of Cu at 240–285 ℃, confirming the inferred heating temperature range. Additionally, at these temperatures, the gold layer was formed through the solid-state reaction of the gold amalgam and was bonded to the substrate through the diffusion of Cu. [ABSTRACT FROM AUTHOR]

In this research article, Zr-MOFs based copper complex as a novel heterogeneous and porous catalyst was designed and prepared. The structure of catalyst has verified by various techniques such as FT-IR, XRD, SEM, N2 adsorption–desorption isotherms (BET), EDS, SEM-elemental mapping, TG and DTG analysis. UiO-66-NH2/TCT/2-amino-Py@Cu(OAc)2 was used as an efficient catalyst in the synthesis of pyrazolo[3,4-b]pyridine-5-carbonitrile derivatives. The aromatization of titled molecules is performed via a cooperative vinylogous anomeric-based oxidation both under air and inert atmospheres. The unique properties of the presented method are short reaction time, high yield, reusability of catalyst, synthesis of desired product under mild and green condition. [ABSTRACT FROM AUTHOR]

Two-dimensional (2D) COF-42 has been prepared and the COF-42/carbon paste electrode (COF-42/CPE) has been applied as a voltammetric sensor for determining copper(II). Different characterization procedures (FTIR, XRD, SEM/EDX, BET, cyclic voltammetry, and electrochemical impedance) have been implemented on the prepared COF-42 and the constructed COF-42/CPE. The central composite design has been applied for optimizing the production and function circumstances of this sensor. The existence of various functional groups in the structure of the COF-42 makes this COF greatly efficient in recognizing Cu(II) and creating stable complexes with it. The COF-42 possesses high porosity and contains various binding sites for strong interaction with copper(II), so the existence of the COF-42 in the sensor assembly decreases the mass transfer resistance in the electrode matrix and also eventuates to the precipitation of a large amount of copper analyte. The precise selection of COF and optimization of sensor preparation and operating conditions has resulted in high sensitivity and selectivity for the constructed sensor. A proper mechanism for sensor performance has been presented and confirmed by SEM/EDX and electrochemical procedures. The linear response range of the fabricated sensor is from 0.001 to 10.0 μM. The detection limit is 2.5 × 10−10 M. The analytical performance features of the proposed sensor have been explored by performing different statistical tests. Sensor performance is not affected by the presence of most potentially interfering species. The interference of silver(I) and mercury(II) was also removed by using a masking agent. Based on the experimental results and statistical tests, it was found that when using the masking agent, the precision and accuracy of the method remains at its previous appropriate value. The ability of the sensor has been confirmed in the analysis of real samples. [ABSTRACT FROM AUTHOR]

New copper-containing borates with the general formula PbCd2–xB6O12:xCu2+ have been prepared by solid-state reactions and characterized by X-ray diffraction and IR spectroscopy. A continuous series of substitutional solid solutions isostructural with monoclinic PbCd2B6O12 (sp. gr. P21/n) has been shown to exist in the range 0 < x ≤ 0.08. Replacing cadmium atoms by copper atoms, which are smaller in size, leads to a linear decrease in unit-cell parameters across the solid solution series. The IR spectroscopy and X-ray diffraction data suggest the presence of BO3 and BO4 anions in the structure of the borates. The thermoluminescence intensity has been measured as a function of activator content in the range 25–400°C. The thermoluminescence intensity in the borates increases with activator content, reaching a maximum at x = 0.06, and decreases at higher doping levels. The powder borates studied here can be used as a key component of new luminescence materials. [ABSTRACT FROM AUTHOR]

Ceramic powders of Cu doped lead Titanate (Pb0.5Cu0.5TiO3) are synthesized through a solid-state reaction method at high-temperature. Different percentage of ceramic filler into the polymer matrix was prepared by solution casting techniques. The structural studies of this polymeric composite were characterized by the X-ray diffraction technique and a tetragonal phase was found. Moreover, the surface morphology of this material was done by scanning electron microscopy. The impedance studies of this polymeric composite were characterized by an LCR meter between the frequencies range 102 and106 Hz. The modulus study of the material was done between the frequency ranges 102 and106 Hz. The variation of ac conductivity with frequency at different temperatures satisfied Jonscher's universal power law. [ABSTRACT FROM AUTHOR]

The exploitation of various biomaterials for the biosynthesis of nanoparticles is considered as green technology as it does not involve any harmful chemicals. The present study reports the synthesis of copper nanoparticles which involves non-pathogenic bacterial strain Pseudomonas stutzeri, isolated from soil. These copper nanoparticles are further characterized for size and shape distributions by ultraviolet-visible spectroscopy, x-ray diffraction, and high resolution transmission electron microscopy techniques. The results showed that the particles are spherical and quite stable in nature and shows surface plasmon resonance clearly featured in the optical spectra in visible region. [ABSTRACT FROM AUTHOR]

A copper (I) polymer, [Cu2Mg(pzdc)2(H2O)5•2H2O]n (pzdc = 2,3-Pyrazinedicarboxylic acid), was synthesized by solvothermal method. The complex was characterized using X-ray diffraction (XRD), fourier transform infrared spectroscopy (FT-IR), ultraviolet-visible spectrophotometry (UV-Vis), and element analysis. X-ray crystal structure analysis reveals that the complex is a two-dimensional coordination polymer. The photophysical and luminescent properties of the complex were investigated. At room temperature, the complex exhibits reversible double strands cyclic voltammogram and displays efficient blue emission with peak maxima at 468 nm. Catalytic liquid phase oxidation of dyes and glyphosate was carried out using the copper (I) polymer as catalyst and H2O2 as oxidant. Degradation efficiencies were evaluated by varying the reaction conditions (i.e. illumination and oxidant). In the degradation reactions, the polymer exhibits high degradation efficiency within a short reaction time under the optimum reaction conditions. Furthermore, the reusability of the catalyst is excellent, showing no activity loss in four repeated cycles. The possible reaction mechanism catalyzed by the polymer was inferred on the basis of the results of electron spin resonance (ESR), electrochemical and ion chromatography analyses (IC). [ABSTRACT FROM AUTHOR]

Copper nanowires have been synthesized at different pH values through the template assisted electrodeposition technique using polycarbonate track-etch membranes as scaffolds. The effect of pH (0.8-2.8) of the electrolyte on structure, morphology, composition and deposition rate of copper into the pores of the template, while keeping other electrochemical conditions same, was investigated. X-ray diffraction analysis confirmed the face centered cubic phase of synthesized nanowires. With the change in pH, no shift in peaks was observed except the inclusion of an additional peak of copper oxide in nanowires synthesized at pH 2.8. The nanocrystallite size, strain, lattice stress and energy density were evaluated by X-ray analysis. Field emission scanning electron microscopy images revealed that nanowires obtained at pH 0.8, 1.1 and 1.4 showed incomplete deposition in the pores of the membrane whereas, the nanowires obtained at pH 1.7 were densely stacked, vertically aligned and uniform along the diameter and that obtained from pH 2.0-2.8 had overdeposition on their top. An increase in deposition rate was observed with the increase in pH value. The average diameter of Cu nanowires was found to be ~ 105 nm. The electrical conductivity of as-grown nanowires was observed to decrease 13-fold as the transition from bulk values to the nanosystem. Nanowires prepared at pH of 1.7 were characterized for their field-emission properties. A very large field-enhancement factor of ~ 10,855 was obtained indicating that Cu nanowires grown by reported technique shows outstanding potential as efficient field-emitters for flat panel displays. [ABSTRACT FROM AUTHOR]

Abstract: Nano-functionalization of textiles has been developed for various applications that should be adapted to reduce the utilization of chemicals, energy, processing steps and time of the finishing in view of the ecological and economical restrictions. In the current study, for the first time, we introduce an eco-friendly, feasible and facile approach for producing synthetic or natural fabrics with multi-functional properties via green assembling of copper-based nanoparticles in one single step without the use of further chemicals or external physical apparatuses. Copper acetate was only used as a metal salt with textile substrate as a template at boil without using other chemicals. X-ray diffraction analysis, energy-dispersive X-ray spectroscopy, mapping, field-emission scanning electron microscope images, Fourier transform infrared spectra and UV-Vis spectrum were proved the formation of copper or copper oxide nanoparticles on the textile substrates. The treated fabrics indicated very good properties regarding antibacterial, self-cleaning, photocatalytic, UV protection and coloring effect with enhanced mechanical properties. Finally, this novel method can be applied as a cleaner, economic and large-scale strategy for nano-functionalization of textiles and polymers based on copper/copper oxide nanoparticles in the related industries.Graphical abstract: [ABSTRACT FROM AUTHOR]

In this report, CuFeO nanoparticles were synthesized using chemical co-precipitation method. The tetragonal phase formation of CuFeO nanoparticles was confirmed by X-ray diffraction technique with its Rietveld refinement data, TEM and SEM analysis. The particle size of CuFeO nanoparticles was found to be 6.4 ± 1 nm using Scherrer formula and TEM analysis. The surface morphology and porosity of CuFeO nanoparticles and its sensing device were analysed using TEM, SEM and AFM images. The CuFeO sensor was tested towards NH, NO, SO and smoke as change in conductance in terms of impedance spectroscopy with the help of electrochemical workstation. The performance of the sensor was investigated in the form of sensitivity, response and recovery time. The sensitivity was observed in the following order NH > NO > SO > smoke with response and recovery time 8 s and 5 min respectively. [ABSTRACT FROM AUTHOR]

Electrodeposited SiO electrodes were shown to be photoactive and exhibit n- and p-type effects for electrodes placed in aqueous and organic solutions, respectively. As seen by Fourier transform infrared (FTIR) spectroscopy and X-ray photoelectron (XPS) spectroscopy, the mechanism of the electrodeposition included reactions with the used electrolyte as well as with traces of water as sources of oxygen and hydrogen. The lowest band gap energy ( E ) of the films of approximately 1.6 eV was observed for the film electrodeposited at −2.5 V in comparison to 1.9 eV for the films obtained at −2.25 and −2.75 V. The depth profiles of Si and O in the films were registered by XPS, secondary ion mass spectrometry (SIMS), and glow discharge optical emission spectroscopy (GD-OES), which showed that Si and O were relatively uniformly distributed across the entire layer of the film. The n-type photoactivity was associated with the evolution of oxygen from the aqueous solution, and the p-type was attributed to the reductive deterioration of the amorphous SiO deposit and simultaneous photodecomposition of the electrolyte. Graphical Abstract: [ABSTRACT FROM AUTHOR]

Cobalt ferrite, copper and bismuth co-substituted cobalt ferrite nanoparticles are prepared by solution combustion method. The synthesized compounds are authenticated by powder X-ray diffraction, Fourier transform infrared spectroscopy, Scanning electron microscopy-Energy dispersive X-ray analyser and Vibrating sample magnetometer. Particle size, lattice parameter, saturation magnetization and coercivity as a function of bismuth and copper substitution in cobalt ferrite nano particles are studied. Lattice parameter and dielectric constant are increased due to the substitution of bismuth in cobalt ferrite. Catalytic activity of the synthesized compounds are tested for the reduction of 4-nitrophenol (4-NP) to 4-aminophenol (4-AP). The conversion of nitrophenol to amino phenol is achieved in seconds using the substituted cobalt ferrite compounds. [ABSTRACT FROM AUTHOR]

Organic-inorganic nanocomposite was obtained after the incorporation of cupric oxide (CuO) nanoparticles in a host matrix based on pyrogallol and formaldehyde (PF) using sol-gel method. The material was subjected to heat treatment under inert atmosphere at 650 °C during 2 h to obtained PF/Cu-650 nanocomposite. The X-ray diffraction analysis exhibited the presence of two phases: metallic copper Cu and graphite C. The voltage-current V(I) characteristics present a negative differential resistance at room temperature. The evolution of the conductivity as a function of measurement temperature indicates the dominance of the three dimensions Godet-variable range hopping transport model. The alternative current conductance was investigated using admittance spectroscopy; the obtained curves show the presence of hopping conduction mechanism. The Nyquist diagrams were used to identify an equivalent circuit and the fundamental parameters of the circuit are determined with the aim to study the contributions of the grains and grain boundaries to the conductivity. [ABSTRACT FROM AUTHOR]

Sub- and over-stoichiometric TiN films have been processed by varying the flow rate of nitrogen in the chamber. In order to study the copper diffusion through Ti and TiN layers, these layers were systematically coated with a Cu layer 50 nm thick. For some of the stacks a SiN layer 50 nm thick is deposited over the Cu layer. Specimens were isothermally heat treated from 240 to 430 °C under primary vacuum and under argon atmosphere. Cu/BL/SiO/Si and SiN/Cu/BL/SiO/Si stacks (where BL = Ti or TiN) where characterized by transmission electron microscopy with energy dispersive X-ray analysis, time-of-flight secondary ion mass spectrometry and X-ray diffraction. These characterizations indicate clear differences on the copper diffusion through the system depending on the film compositions and microstructures as well as on the annealing temperature. The diffusion of copper through the TiN and the reactivity between Cu and TiN films strongly depend on their composition but also on the processing conditions of these films. Moreover, the performances of some of these films, with respect to copper diffusion and/or reaction, are degraded as the temperature increases from 260 to 430 °C. Diffusion of copper through the TiN films as well as reaction conditions are studied and discussed. [ABSTRACT FROM AUTHOR]

In this work, the effect of copper through-silicon via (TSV) interconnect diameter on stress buildup in Cu TSVs was experimentally determined using a synchrotron-based X-ray microdiffraction technique. A single chip with different Cu TSV diameters (3, 5, and 8 µm), all having the same depth and processing conditions was studied. Prior to the measurements, the chip was annealed at 420 °C (30 min), leading to microstructurally stable Cu TSVs. The mean measured hydrostatic stresses were (190 ± 25) MPa (3 µm diameter), (138 ± 19) MPa (5 µm diameter), and (209 ± 26) MPa (8 µm diameter), respectively. No clear relationship between the measured stress and Cu TSV diameter was observed. This trend is attributed to the operation of stress relaxation mechanisms in the polycrystalline Cu TSVs, which includes plastic deformation, grain boundary sliding, void formation/growth, and rate-controlled dislocation motion, which are often neglected in reported finite element analysis studies. Additionally, this study highlights that the thermo-mechanical behavior of Cu TSVs is significantly influenced by their thermal history. [ABSTRACT FROM AUTHOR]

Pure and Cu-doped zinc oxide (ZnO) nanoparticles were prepared using a chemical method. The dopant concentration (Cu/Zn in atomic percentage (wt%)) is varied from 0 to 3 wt%. Structural characterization of the samples performed using X-ray diffraction (XRD) confirmed that all the nanoparticles of zinc oxide are having polycrystalline nature. Morphological studies were conducted using field emission scanning electron microscopy (FESEM) to confirm the grain size and texture. Electrical measurements showed that the AC conductivity initially decreases and then rises with increasing Cu concentration. The UV-Vis studies showed absorbance peaks in the 200-800 nm region. It is found that the absorbance does not significantly change with doping. This fact is further confirmed from the band-gap calculations using the reflectance graphs. When analysed in terms of Burstein-Moss shift, an increase of band gap from 3.42 to 3.54 eV with increasing Cu concentration is observed. In the Photoluminescence (PL) studies a red-shift is observed with increasing dopant concentration. [ABSTRACT FROM AUTHOR]

This study aims to examine the effect of annealing conditions on nitinol (NiTi) characteristics and applies this knowledge to fabricate a NiTi-copper shape memory alloy bimorph actuator. The effect of the annealing conditions was investigated at various temperatures, i.e., 500, 600, and 650 °C, for 30 min. With the characterizations using x-ray diffraction, energy dispersive spectroscopy, and differential scanning calorimetry techniques, the results showed that annealing temperatures at 600 and 650 °C were able to appropriately form the crystalline structure of NiTi. However, at these high annealing temperatures, the oxide on a surface was unavoidable. In the fabrication of actuator, the annealing at 650 °C for 30 min was chosen, and it was performed at two pre-stressing conditions, i.e., straight and curved molds. From static and dynamic response experiments, the results suggested that the annealing temperature significantly affected the deflection of the actuator. On the other hand, the effect of pre-stressing conditions was relatively small. Furthermore, the micro gripper consisting of two NiTi-copper bimorph actuators successfully demonstrated for the viability of small object manipulation as the gripper was able to grasp and hold a small plastic ball with its weight of around 0.5 mg. [ABSTRACT FROM AUTHOR]

The effects of copper particles dispersed into BiSbTeSe nanopowders and sintered by open die pressing (ODP) have been investigated. Submicrometric copper particles were obtained by decomposing copper acetate molecules dispersed into chalcogenides nanopowders. The acetate powders were decomposed during the sintering process at 390 °C obtaining a fine dispersion of copper particles with dimensions in the order of 500 nm. Contents up to 0.2 wt.% of copper were investigated. ODP, previously introduced as a forming process for sintering and texturing p-type (BiSb)Te nanopowders, has been applied to n-type chalcogenide: the mixed alloy nanopowders and copper acetate were compacted inside a metallic protective shell and fast pressed between two heated plates, keeping the composite under load for sintering. ODP processing ensures complete consolidation of nanopowders and material texturing with the basal (00 l) planes of the hexagonal crystal cell oriented parallel to the plates. The X-ray diffraction pattern shows an orientation factor, f, obtained by the Lotgering method, up to 64 %. Thermoelectric performance of the samples was measured by the Harman method in the range of 20-170 °C. Figure of merit ( ZT) behavior with temperature was improved in copper-dispersed samples showing a shift of the maximum value at higher temperatures. This effect can be mainly associated with an improvement of electrical conductivity, due to the presence of the copper particles. [ABSTRACT FROM AUTHOR]

Bimetallic Pt-Cu carbon-supported catalysts (Pt(Cu)/C) were prepared by electroless deposition of Cu on a high surface area carbon powder support, followed by its partial exchange for Pt; the latter was achieved by a galvanic replacement process involving treatment of the Cu/C precursor with a chloroplatinate solution. X-ray diffraction characterization of the Pt(Cu)/C material showed the formation of Pt-rich Pt-Cu alloys. X-ray photoelectron spectroscopy revealed that the outer layers are mainly composed of Pt and residual Cu oxides, while metallic Cu is recessed into the core of the particles. Repetitive cyclic voltammetry in deaerated acid solutions in the potential range between hydrogen and oxygen evolution resulted in steady-state characteristics similar to those of pure Pt, indicating the removal of residual Cu compounds from the surface (due to electrochemical treatment) and the formation of a compact Pt outer shell. The electrocatalytic activity of the thus prepared Pt(Cu)/C material toward methanol oxidation was compared to that of a commercial Pt/C catalyst as well as of similar Pt(Cu)/C catalysts formed by simple Cu chemical reduction. The Pt(Cu)/C catalyst prepared using Cu electroless plating showed more pronounced intrinsic catalytic activity toward methanol oxidation than its counterparts and a similar mass activity when compared to the commercial catalyst. The observed trends were interpreted by interplay between mere surface area effects and modification of Pt electrocatalytic performance in the presence of Cu, both with respect to methanol oxidation and poisonous CO removal. [ABSTRACT FROM AUTHOR]

Nanostructured pure-TiO2 and Cu3%-TiO2 were successfully synthesized via co-precipitation method. The X-ray diffraction (XRD) result proves that the synthesized sample were predominantly in anatase phase with size in the range of 8~16 nm, which are in good agreement with the transmission electron microscopy data. Owing to doping of copper, not only did the thermal stability of the TiO2 decrease, but also a significant decrease in its particle size and a shift of the adsorption edge to a higher wavelength region appear. The activity of both pure-TiO2 and Cu3%-doped TiO2 was tested to study their ability to decolorize congo red (CR) dye in aqueous solution. We observed that the CR dye was decolorized faster by Cu3%-TiO2 than pure-TiO2. Results of this study demonstrate a potential application of the synthesized sample for decolorizing dye pollutants from aqueous waste. [ABSTRACT FROM AUTHOR]

3-Thiopropionic acid (TPA) capped ZnS:Cu nanocrystals have been successfully synthesized by simple aqueous method. Powder X-ray diffraction (XRD) studies revealed the particle size to be 4·2 nm. Surface characterization of the nanocrystals by FTIR spectroscopy has been done and the structure for surface bound TPA based on spectral analysis was proposed. The optical studies were done using UV-VIS spectroscopy and particle size and diameter polydispersity index (DPI) were calculated. Photoluminescence (PL) spectrum reveals emission related to the transition from conduction band of ZnS to t level of Cu. Electron microscopy was also done by scanning electron microscopy (SEM). [ABSTRACT FROM AUTHOR]

Free standing powders of copper-doped Cd1− xZn xS (0 ≤ x ≤ 0.5) quantum dots (QDs) were synthesized using a simple chemical co-precipitation method. The copper concentration was varied from 0.01 to 10 at. wt% of Cd2+. X-ray diffraction and transmission electron microscope were used for crystallographic and morphological analyzes. Room temperature time resolved luminescence spectra were recorded using high peak power, pulsed N2-laser excitation. Decay time values for bluish green and yellow emission have been calculated from recorded luminescence decay curves. Decay time dependence on Cu2+ and Zn2+ concentrations have been studied in detail. These QDs will have wide applications as nanophosphors, solar cells, photocatalysts and chemical sensors. [ABSTRACT FROM AUTHOR]

The cross-interaction between Sn/Cu and Sn/Au interfacial reactions in an Au/Sn/Cu sandwich structure was studied. Field-emission electron probe microanalysis (FE-EPMA) revealed that the Cu content in the three Au-Sn phases (AuSn, AuSn2, and AuSn4) was very low, less than 1 at.%. This means␣that Cu from the opposite Cu foil did not participate in the interfacial reaction at the Sn/Au interface. On the opposite Sn/Cu side, Au-substituted (Cu,Au)6Sn5 formed within the initial 1 min of reflow. With prolonged reflow, the Au content in the Au-substituted (Cu,Au)6Sn5 increased and it transformed into a Cu-substituted (Au,Cu)Sn phase with 25 at.% Cu after 1 min of reflow at 250°C. The x-ray diffraction (XRD) pattern confirmed the phase transformation of Au-substituted (Cu,Au)6Sn5 to Cu-substituted (Au,Cu)Sn phase. In addition, there was greater Au consumption in the Au/Sn/Cu sandwich joint structure than in the single Au/Sn reaction case, due to some of the Au participating in the opposite Sn/Cu interfacial reaction. [ABSTRACT FROM AUTHOR]

The influence of BaCu(B2O5) (BCB) addition on the sintering temperature and microwave dielectric properties of ZnO-2TiO2-Nb2O5 (ZTN) ceramic has been investigated using dilatometry, x-ray diffraction, scanning electron microscopy, and microwave dielectric measurements. A small amount of BCB addition to ZTN can lower the sintering temperature from 1100°C to 900°C. The reduced sintering temperature was attributed to the formation of the BCB liquid phase. The ZTN ceramics containing 3.0 wt.% BCB sintered at 900°C for 2 h have good microwave dielectric properties of Q × f = 19,002 GHz (at 6.48 GHz), εr = 45.8 and τ f = 23.2 ppm/°C, which suggests that the ceramics can be applied in multilayer microwave devices, provided that Ag compatibility exists. [ABSTRACT FROM AUTHOR]

Three series of NiMgCuZn ferrites were prepared by conventional sintering process. The formation of single phase in these ferrites was confirmed by x-ray diffraction. Initial permeability measurements on these samples were carried out in the temperature range of 30–400°C. The effect of the external applied stress on the open magnetic circuit type coil with these ferrites was studied by applying uniaxial compressive stress parallel to magnetizing direction and the change in the inductance was measured. The variation of ratio of inductance (ΔL/L)% increases upto certain applied compressive stress and there after it decreases, showing different stress sensitivities for different compositions of ferrites studied in the present work. With a view to develop stress insensitive NiMgCuZn ferrite, a low stress sensitivity composition among all the ferrites studied was chosen and different amounts of SiO2 were added to it and a series of ferrite compositions were prepared. The variation of ratio of inductance (ΔL/L)% with external applied compressive stress was examined. These results show that, 0.05 wt% SiO2 added Ni0.3Mg0.3Cu0.1Zn0.3Fe2O4 ferrite exhibited stress insensitivity. It was noticed that addition of SiO2 was found to be effective in reducing the stress sensitivity. This was confirmed from the elastic behaviour studies at room temperature on these ferrite samples. These studies were carried out to develop a ferrite composition for its use as core material for microinductor applications. [ABSTRACT FROM AUTHOR]

In this work, an electroless CoWP film deposited on a silicon substrate as a diffusion barrier for electroless Cu and silicon has been studied. Four different Cu 120 nm/CoWP/Si stacked samples with 30, 60, 75, and 100 nm electroless CoWP films were prepared and annealed in a rapid thermal annealing (RTA) furnace at 300°C to 800°C for 5 min. The failure behavior of the electroless CoWP film in the Cu/CoWP/Si sample and the effect of CoWP film thickness on the diffusion barrier properties have been investigated by transmission electron microscopy (TEM), scanning electron microscopy (SEM), X-ray diffraction (XRD), and sheet resistance measurements. The composition of the electroless CoWP films was 89.4 at.% Co, 2.4 at.% W, and 8.2 at.% P, as determined by energy dispersive X-ray spectrometer (EDS). A 30 nm electroless CoWP film can prevent copper penetration up to 500°C, and a 75 nm electroless CoWP film can survive at least up to 600°C. Therefore, increasing the thickness of electroless CoWP films effectively increases the failure temperature of the Cu/CoWP/Si samples. The observations of SEM and TEM show that interdiffusion of the copper and cobalt causes the failure of the electroless CoWP diffusion barriers in Cu/CoWP/Si during thermal annealing. [ABSTRACT FROM AUTHOR]

Cu–Ag bimetallic nanoparticles with atomic ratio of 2.1:1 and diameter in the range of 15–30 nm were decorated on acid-treated multi-walled carbon nanotubes by a chemical reduction method, which was characterized by transmission electron microscope (TEM), X-ray powder diffraction (XRD), X-ray photoelectron spectroscopy (XPS) and high-resolution transmission electron microscopy (HRTEM). The Cu–Ag/MWNTs nanocomposites were used to construct a modified electrode toward biosensing of H2O2 with a high sensitivity. The catalytic ability of MWNTs/Cu–Ag toward H2O2 was much better than that of MWNTs/Cu and MWNTs/Ag, which indicated that there is a cooperation effect between Cu and Ag. [ABSTRACT FROM AUTHOR]

Highly thermally stable amorphous TaxNi1-x (x = 0.25 and 0.75) thin films were deposited on Si and Si/SiO2 substrate by magnetron dc sputtering, and the performance of films (20-nm thick) as barriers for copper (Cu) interconnection was evaluated. The failure behaviors of the films were elucidated using a four-point probe, x-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), and Auger emission spectrometry (AES). A highly (111) textured Cu film could be obtained when Cu was deposited on Si/Ta0.25Ni0.75 and Si/SiO2/Ta0.25Ni0.75 substrates. The failure temperatures of Si/Ta0.25Ni0.75/Cu- and Si/Ta0.75Ni0.25/Cu-stacked films were 550°C and 600°C, respectively. Failure of the studied films initiated the penetration of Cu into the Si/TaxNi1-x interface and triggered the partial dissociation of the TaxNi1-x barrier layer, forming Cu3Si precipitates, Ni-silicide and Ta-silicide. Increasing the Ta content enhanced the microstructural and thermal stability of the stacked films, markedly improving barrier properties. The experimental findings demonstrated that the barrier characteristic of Ta0.75Ni0.25 was substantially superior to that of Ta0.25Ni0.75. [ABSTRACT FROM AUTHOR]

Immersion of corroded copper artefacts in dilute sodium sesquicarbonate solution is a well-recognized stabilization technique—especially in the conservation of objects recovered from marine environments and therefore saturated with chlorides. Here we describe three linked experiments performed to investigate a variation on this treatment, involving the application of a low potential to the artefact in order to drive the chloride extraction process. This includes a new spectroelectrochemical approach which allows 2-D pseudorandom X-ray reflection diffraction patterns to be obtained without interrupting the reaction in solution. Experiments were carried out on synthetically produced chloride layers on copper (nantokite and atacamite). We show that a thick chloride layer is, in general, replaced by a thin cuprite layer through a mechanism which involves detachment of the chloride crystallites from the surface prior to dissolution. [ABSTRACT FROM AUTHOR]

To understand the effect of line width on textural and microstructural evolution of Cu damascene interconnect, three Cu interconnects samples with different line widths are investigated. According to x-ray diffraction (XRD) results, the (111) texture is developed in all investigated lines. Scattered {111}<112> and {111}<110> texture components are present in 0.18-µm-width interconnect lines, and the {111}<110> texture was developed in 2-µm-width interconnect lines. The directional changes of the (111) plane orientation with increased line width were investigated by XRD. In addition, microstructure and grain-boundary character distribution (GBCD) of Cu interconnect were measured using electron backscattered diffraction (EBSD) techniques. This measurement demonstrated that a bamboo-like microstructure is developed in the narrow line, and a polygranular structure is developed in the wider line. The fraction of ∑3 boundaries is increased as the line width increases but is decreased in the blanket film. A new interpretation of textural evolution in damascene interconnect lines aider annealing is suggested, based on the state of stress and growth mechanisms of Cu deposits. [ABSTRACT FROM AUTHOR]

Free-standing discontinuous Cu-line patterns varying in line widths and interline distances in the range of a few micrometers were manufactured by combining photolithography and electrochemical deposition. Two principally different seed layers, polycrystalline Au and X-ray amorphous Ni-P, were applied prior to electrodeposition of the Cu lines as well as continuous Cu films, which were deposited as reference. The effect of the seed layer and the influence of the pattern design on surface topography and morphology of the deposits were studied by means of light optical and scanning electron microscopy (SEM). The growth behavior is related to the developing crystallographic texture of Cu-line patterns and continuous films, as determined from calculated orientation distribution functions (ODFs) on the basis of X-ray diffraction (XRD) pole figure measurements. While strong crystallographic textures of Cu lines on polycrystalline Au were observed with pattern-dependent differences to continuous films, almost no preferred grain orientations develop both for Cu lines and corresponding continuous films deposited on amorphous Ni-P. [ABSTRACT FROM AUTHOR]

The anisotropic spread of the central peak in a (111) pole figure by x-ray diffraction (XRD) was observed for damascene Cu lines of 0.18-2 µm in width and 0.5 µm in depth. The spread originates from the existence of slightly tilted (111) grains because of inclined sidewalls. The tilted (111) orientation is favorable only for polygranular clusters whose sidewall energies can be minimized simultaneously. Consequently, bamboo grains have an exact <111> orientation, while the polygranular clusters have a tilted <111> orientation. Using this concept, the volume fraction of the bamboo grains and polygranular clusters in the damascene Cu lines were quantified using the XRD pole plots. [ABSTRACT FROM AUTHOR]

The effects of partial indium and iron substitutions for copper on the polymorphic transformations of Cu1.90S was studied by x-ray diffraction. The results demonstrate that the incorporation of In or Fe drastically changes the sequence of polymorphic transformations and stabilizes the high-temperature, FCC phase to room temperature. [ABSTRACT FROM AUTHOR]

Single layers of Cu and In were deposited onto Mo coated glass substrates by radio frequency sputtering. The Cu11In9 phase has been found to be the majority phase in these precursors. The selenization of the sputtered layers has been achieved by depositing a 1 μm Se layer onto the precursor by thermal evaporation followed by an annealing in vacuum. Samples were annealed at different temperatures varying between 100–600°C at intervals of 50°C. The chalcopyrite structured ternary phase of CuInSe2 with a significant amount of preferential orientation in the (112) direction was obtained in samples annealed at 400°C or above. Morphological, compositional and structural analyses of the samples annealed at different temperatures were performed using a variety of complementary techniques. The results were analysed to explain the growth of CuInSe2 on the selenization of sputtered Cu-In precursors. The occurrence of various binary phases of Cu-In, Cu-Se and In-Se in different annealing temperature ranges has also been investigated. The phenomenon of volume expansion in CuInSe2 on selenization has been found to manifest itself as a shift in the characteristic (110) X-ray diffraction peak of Mo. [ABSTRACT FROM AUTHOR]

Microstructure is an important factor influencing the reliability of thin film interconnects. The microstructure of copper films is of particular interest because of its use in numerous electronic applications. Pole figure x-ray diffraction and transmission electron microcopy were conducted on copper films deposited by several techniques: sputtering, partially ionized beam deposition, chemical vapor deposition, evaporation, and electroplating. Quantitative texture data are determined from fiber texture plots. A typical copper film consists of three texture components: (111), (200), and random. (220) and (511) texture components are possible under some deposition conditions. Compared to aluminum films, the fraction of the random texture component and the distribution of the (hkl) components in copper films are relatively large. Bimodal grain size distributions are observed in some films. [ABSTRACT FROM AUTHOR]

Focuses on the in situ combustion synthesis of ultrafine TiB2 particles reinforced Cu matrix composite. Discussion of the microstructure of Cu matrix; Presentation of the X-ray diffraction patterns of the synthesized Cu-TiB2 composite.

A new, simple, rapid, selective, and environmentally friendly method is proposed for the determination of Cu(II) ions based on the formation of the complex between these ions and salophen as the ligand followed by the dispersive liquid-liquid microextraction of the neutral hydrophobic complex formed in the organic phase and flame atomic absorption spectrophotometric detection. Various factors including the pH of the sample solution, concentration of salophen as the complexing reagent, type and volume of the extraction and disperser solvents, and extraction time affecting the extraction efficiency of Cu(II) ions and its subsequent analytical signal were studied and optimized. Under the optimized experimental conditions, the detection limit (3σ) and the enrichment factor were obtained to be 0.60 μg L−1 and 49, respectively, for 10.0 mL of the sample solution. The consumptive index was 0.20 mL and the calibration graph was linear in the range of 3.0-120 μg L−1. The relative standard deviations for six replicate measurements of 5.0, 20.0, and 50.0 μg L−1 of Cu(II) ions were 4.1%, 1.5%, and 1.8%, respectively. The proposed method was also successfully applied for the extraction and determination of Cu(II) ions in different water and food samples with satisfactory results. [ABSTRACT FROM AUTHOR]

We report the synthesis and characterization of Cu2ZnSnS4 (CZTS) with controlled phase purity. The precursor was first prepared using sequential electrodeposition of Cu, Zn, and Sn in different orders. The Cu/(Sn+Zn) ratio in each stacking order was also varied. The precursor was subjected to annealing at 200°C and sulfurization at 500°C in a 5%-H2S/Ar atmosphere for the formation of CZTS. The phase evolutions during the electrodeposition and annealing stages, and the final phase formation at the sulfurization stage were examined using both x-ray diffractometry and Raman spectroscopy, both of which are shown to be complimentary tools for phase identification. Detailed growth path is therefore reported. We also demonstrate by controlling the stacking order and the Cu/(Sn+Zn) ratio, CZTS with a phase purity as high as 93% is obtained. [ABSTRACT FROM AUTHOR]

Cuprous oxide (Cu2O) nano- and microstructures possess unique properties that may find a variety of applications. Environmentally benign synthesis of Cu2O with well-controlled morphology is highly desirable. In this study, Cu2O crystals with tunable shapes are synthesized using cellulose nanofibrils (CNFs) as a shape regulator and the sole reducing agent in aqueous environment. By simply increasing Cu2O precursor concentration, the Cu2O crystals evolved from octahedra to cuboctahedra, and finally cubes, accompanied with increasing size from nano- to microscale. The selection of Cu chelating agent (sodium tartrate or potassium sodium tartrate) affected the crystal growth rate. Transition in the relative intensities of the (111) and the (200) crystalline peaks in their XRD patterns was consistent with the morphology change. During the growth of crystals, CNFs were preferably bound to the {111} crystalline facet. The introduction of KBr to the reaction system produced short hexapods. The resultant CNF-Cu2O hybrids were incorporated into waterborne polyurethane (WPU) films. Even with 0.5 wt% CNF-Cu2O, the WPU film showed significant enhancement in modulus, strength and elongation at break. This work proves the possibility of controlled growth of Cu2O particles aided by CNFs and provides a new strategy for improving the performance of eco-friendly WPU films. [ABSTRACT FROM AUTHOR]