Deposition Of Metal Layers Research Articles

Developing a robust sensor for infrared imaging bolometers.

A new type of large area sensor for infrared imaging bolometers has been developed. It replaces the thin and fragile free-standing metal foils, which typically have been used, with a multi-layer coated sapphire (or diamond) substrate. Sapphire is transparent to mid-infrared wavelengths, is robust against transients, and can be thick enough to even be the vacuum window. The primary radiation absorber is still a thin deposited metal layer, but now it is partially insulated from the supporting sapphire substrate by a black (carbon-based) layer, which also acts as a blackbody remitter. Test results indicate 6× more noise equivalent power density (estimated NEPD = 23 W/m2 at 5ms camera exposure time, foil temperature decay time 60ms) for a 2μm gold-coated sapphire disk compared to estimated NEP = 4 W/m2 at 1.8ms exposure time, with foil decay time 420ms, for a nominal 2.5μm thick platinum-free-standing foil.

Bond strength of epoxy-based composites at the interface with surface deposited metal layer: A comparative study with different dimensional fillers

With the complexity of the working environment, pure epoxy resin can no longer meet the requirements, and the weak interfacial bonding between metal layer and epoxy-based composites limits its development. In this work, we propose a novel molecular grafting modification technique by using the active functional groups of polymers, which can apply to epoxy-based composites with various fillers to improve the adhesive strength of the interface between the metal film and matrix. 3D surface profile and surface wettability were used to characterize the effect of fillers on the surface of epoxy composites. Scanning electron microscope (SEM) and Raman spectroscopy were utilized to judge the interface failure modes of the composites. Peeling test and surface-enhanced Raman scattering (SERS) were conducted to examine how fillers affected adhesion. The results showed that silane grafting substantially improved the bonding between the epoxy-based composite matrix and the metal layer without the need for alkaline washing and palladium (Pd) activation steps on the substrate. The average adhesive strength can reach a maximum of 17.76 N/cm. The study also revealed the effect of filler size on the interfacial adhesive strength. The interfacial adhesive strength was increased by two dimensional lamellar materials, decreased by one-dimensional tubular materials, and remained unaffected by zero-dimensional spherical materials. This study may have positive implications for improving interfacial bonding between metal and polymer composite surfaces.

Ultrahigh Potassium Storage Capacity of Ca2Si Monolayer with Orderly Multilayered Growth Mechanism.

As the rising renewable energy demands and lithium scarcity, developing high-capacity anode materials to improve the energy density of potassium-based batteries (PBBs) is increasingly crucial. In this work, a unique orderly multilayered growth (OMLG) mechanism on a 2D-Ca2Si monolayer is theoretically demonstrated for potassium storage by first-principles calculations. The global-energy-minimum Ca2Si monolayer is a semiconductor with isotropic mechanical properties and remarkable electrochemical properties, such as a low potassium ion migration energy barrier of 0.07eV and a low open circuit voltage ranging from 0.224 to 0.003V. Most notably, 2D-Ca2Si demonstrates an ultrahigh theoretical specific capacity of 5459mAhg-1 and a total specific capacity of 610mAhg-1, reaching up to 89% of the capacity of a potassium metal anode. Remarkably, the OMLG mechanism facilitates stable, dendrite-free deposition of hcp-K metal layers on the 2D-Ca2Si surface, where the ultrahigh and gradually converging lattice match as the layers increase is the key to achieving theoretically near-infinite growth. The study theoretically demonstrates the Ca2Si monolayer a highly promising anode material, and offers a novel potassium storage strategy for designing 2D anode materials with high specific capacity, rapid potassium-ion migration, and good safety.

Dual-Mode Comb Plasmonic Optical Fiber Sensing.

Surface plasmon (SP) excitation in metal-coated tilted fiber Bragg gratings (TFBGs) has been a focal point for highly sensitive surface biosensing. Previous efforts focused on uniform metal layer deposition around the TFBG cross section and temperature self-compensation with the Bragg mode, requiring both careful control of the core-guided light polarization and interrogation over most of the C + L bands. To circumvent these two important practical limitations, we studied and developed an original platform based on partially coated TFBGs. The partial metal layer enables the generation of dual-comb resonances, encompassing highly sensitive (TM/EH mode families) and highly insensitive (TE/HE mode families) components in unpolarized transmission spectra. The interleaved comb of insensitive modes acts as wavelength and power references within the same spectral region as the SP-active modes. Despite reduced fabrication and measurement complexity, refractometric accuracy is not compromised through statistical averaging over seven individual resonances within a narrowband window of 10 nm. Consequently, measuring spectra over 60 nm is no longer needed to compensate for small temperature or power fluctuations. This sensing platform brings the following important practical assets: (1) a simpler fabrication process, (2) no need for polarization control, (3) limited bandwidth interrogation, and (4) maintained refractometric accuracy, which makes it a true game changer in the ever-growing plasmonic sensing domain.

Co contamination of Si: Plating & aging

Cobalt has emerged as a vital material in 10 nm technology for localized interconnect layers, potentially offering a compelling alternative to Cu-based interconnects. In this study, we subjected the contamination arising from the presence of cobalt atoms in silicon to comprehensive investigation, employing electron transmission electron microscopy (TEM) observations in conjunction with first-principles calculations. The results show that a dense CoSi layer with a thickness of a few nanometers is formed at the interface of cobalt and Si. The CoSi layer blocks the diffusion of Co atoms into Si. This is due to the semiconducting nature of the covalent bond formed between Co and Si, leading to the emergence of a forbidden zone at the Co/CoSi interface. The diffusion of Co into CoSi is governed by the atomic exchange mechanism, however, the local distortion of the periodic atomic potential due to the presence of the forbidden zone at the Co/CoSi interface hinders the diffusion of Co into Si. Therefore, the deposition of a Co metal layer on a Si chip does not require an additional barrier layer.

Atmospheric pressure plasma jet: Green technology advancements for metals deposition potential

This study explored the utilization of an atmospheric pressure plasma jet (APPJ) for the deposition of metal layers, employing Ar + 2 % H2 as the working gas. The research focuses on three distinct metals - silver (Ag), copper (Cu), and nickel (Ni). Through the application of optical emission spectroscopy, significant peaks of Ar-related and hydrogen-alpha (Hα) species are observed, accompanied by atomic characteristic emission lines specific to Ag, Cu, and Ni, respectively. The XRD examination indicates the successful deposition of metal layers onto the substrates, a confirmation supported by the EDS line scan. Examination of the surface morphology reveals that the metal particles have clustered together, creating a porous structure. The resistivity measurement obtains the values of 5.18, 3.81, and 9.21 μΩ-cm for Ag, Cu, and Ni layers, respectively. Moreover, the paper presents a proposed mechanism for depositing metallic conductive layers using an atmospheric pressure plasma jet (APPJ), elucidating the complex processes inherent in this novel technique.

Metal-Plastic Hybrid Additive Manufacturing to Realize Small-Scale Self-Propelled Catalytic Engines.

Microengines driven by catalytic decomposition of a fuel have been an interesting research area recently due to their diverse applications, such as environmental monitoring and drug delivery. Literature reports a number of studies on this topic where researchers have made various attempts to manufacture such microengines. Some such methods are deposition of catalytic metal layers on sacrificial photoresists, electrochemical deposition of metal layers on polymeric structures, or 3D printing of structures followed by multi-step loading of structures with catalysts. These methods, even though proven to be effective, are tedious, time-consuming, and expensive. To address these issues, herein we report a 3D printing technique to realize microengines in a simple, rapid, and inexpensive single-step process. The printing of various shapes of microengines is achieved using digital light processing printing of a catalyst resin, where Pd(II) acts as a catalyst resin. The proposed integrated molding process can achieve cost-effective preparation of high-efficiency microengines. We demonstrate the locomotion of these microengines in 30% (w/w) H2O2 through the decomposition of H2O2 to generate oxygen to facilitate the self-propelled locomotion. The study characterizes the microengine based on several factors, such as the role of H2O2, Pd, shape, and design of the microengine, to get a full picture of the self-locomotion of microengines. The study shows that the developed method is feasible to manufacture microengines in a simple, rapid, and inexpensive manner to be suitable for numerous applications such as environmental monitoring, remediation, drug delivery, diagnosis, etc., through the modification of the catalyst resin and fuel, as desired.

Modeling the Atomic Layer Deposition of Metal Thin Films: Studying the Surface Reaction Mechanism By Density Functional Theory Simulations

Atomic layer deposition (ALD) is widely used in microelectronics and semiconductor industry to deposit thin films as part of device fabrication in nano- or subnano-dimensions. The key advantages of ALD are the conformality and precise thickness control at the atomic scale, which are difficult for physical or traditional chemical vapor deposition methods. The atomic scale understanding of ALD is vital and essential to design and optimize the deposition process, where density functional theory (DFT) calculations play an important role in providing detailed reaction mechanism, theoretical screening of suitable precursors and estimated growth-per-cycle (GPC).In this study, we show our recent works on DFT calculations of the growth mechanism study of Cobalt (Co) thin film by plasma-enhanced ALD1,2. We first addressed the surface reaction mechanism at the metal precursor pulse and plasma half-cycle on NHx-terminated Co surfaces, which corresponds to the steady growth for the PE-ALD. The adsorption and reactions of metal precursors (CoCp2) on NHx terminated metal surfaces were investigated with the inclusion of van der Waals corrections. The plausible reaction pathways include: precursor adsorption, hydrogen transfer, CpH formation and CpH desorption. The direct Cp dissociation mechanism is not considered on these NHx-terminated metal surfaces due to experimentally observed minimal C impurities at the deposited metal thin films, which indicates that most of the Cp ligand is removed completely. The barrier for proton transfer was calculated using climbing image nudged elastic band (CI-NEB) method.The reactions at the initial stages on typical H:Si(100) surface are investigated to gain atomic insight on the effect of different substrates on the elimination of Cp ligands. Our work is important to reveal the mechanism and feasibility of atomic layer deposition of metals using N-plasma.In addition, we present our recent works3, 4 on the thermal ALD of Co using reducing agent Zn(DMP)2 and thermal ALD of Fe4Zn9 thin film with diethyl zinc (DEZ). Our DFT results show that by selecting suitable reducing agent, we can control the deposited thin films to be Zn-free high quality Co thin film or desired intermetallic thin film with high Zn content.These DFT results are important to understand the reaction mechanism for ALD and provides new knowledge in depositing the thin films by adjusting the reducing agents.

Laser Assisted Electrodeposition of Metals and Alloys

Laser sources are extensively used in surface engineering technology and in materials processing. Their high energy density, excellent directionality and monochromaticity makes them ideal for a wealth of potential uses that require the concentration of a significant amount of energy in a small area. From the electrochemical point of view, one of the most interesting applications for lasers is Laser Assisted Electrodeposition (LAE). Indeed, the high energy density transferred by a laser can locally change the electrochemical state of a surface by inducing photo-electrochemical or thermal-electrochemical effects, triggering thus metal reduction. In addition, it is also possible to pattern the deposited metal layer by scanning the surface of the substrate with the laser, usually with spatial resolution in the range of few micrometers. From the applicative point of view, LAE can be exploited for the selective deposition of metal layers for both decorative and functional uses.LAE can be intended in two ways: the laser can be used to enhance a standard electrolytic deposition process [1, 2], increasing deposition rates by focusing the radiation on the cathode, or it can be used to trigger electrodeposition on freestanding metal surfaces in total absence of any external polarization [1]. The latter approach is the most interesting due to the reduced complexity of the setup required and is made possible by the localized variation of the rest potential induced in the zone of the substrate hit by the light [1]. As a consequence of this variation, metallic ions can be reduced in correspondence of the illuminated zone. The occurrence of this phenomenon, which allows metal deposition without any external power source, has been demonstrated for Cu [1, 3], Ni [3] and Au [4].Despite the work carried out by many research groups, still many aspects of LAE in absence of external polarization remain poorly understood. The aim of the present work is to investigate the possibility to perform LAE with some significant metal-substrate couples. The deposition mechanism is rationalized considering the specific electrochemical properties of the metals involved. In addition to this fundamental characterization, the work also aims at evaluating the industrial applicability of LAE. To this extent, patterned layers of precious metals are deposited on metallic substrates for decorative purposes. Finally, LAE is applied here for the first time to the deposition of alloys.[1] J. C. Puippe et al., J. Electrochem. Soc. 128(12), 2539-2545 (1981)[2] Z. Zhang et al., MDPI Materials 13, 3560 (2020)[3] R. J. von Gutfeid et al., IBM J. Res. Develop. 26(2), 136-144 (1982)[4] Khan et al., NASF Surface Technology White Papers 84(3), 6-13 (2019)

Stearic Acid as an Atomic Layer Deposition Inhibitor: Spectroscopic Insights from AFM-IR.

Modern-day chip manufacturing requires precision in placing chip materials on complex and patterned structures. Area-selective atomic layer deposition (AS-ALD) is a self-aligned manufacturing technique with high precision and control, which offers cost effectiveness compared to the traditional patterning techniques. Self-assembled monolayers (SAMs) have been explored as an avenue for realizing AS-ALD, wherein surface-active sites are modified in a specific pattern via SAMs that are inert to metal deposition, enabling ALD nucleation on the substrate selectively. However, key limitations have limited the potential of AS-ALD as a patterning method. The choice of molecules for ALD blocking SAMs is sparse; furthermore, deficiency in the proper understanding of the SAM chemistry and its changes upon metal layer deposition further adds to the challenges. In this work, we have addressed the above challenges by using nanoscale infrared spectroscopy to investigate the potential of stearic acid (SA) as an ALD inhibiting SAM. We show that SA monolayers on Co and Cu substrates can inhibit ZnO ALD growth on par with other commonly used SAMs, which demonstrates its viability towards AS-ALD. We complement these measurements with AFM-IR, which is a surface-sensitive spatially resolved technique, to obtain spectral insights into the ALD-treated SAMs. The significant insight obtained from AFM-IR is that SA SAMs do not desorb or degrade with ALD, but rather undergo a change in substrate coordination modes, which can affect ALD growth on substrates.

SERS-substrates based on ZnO nanoflowers prepared by green synthesis

ZnO nanoparticles (NPs) with a flower-like morphology, synthesized by an affordable colloidal route using an aqueous fungi extract of Ganoderma lucidum as a reducing agent and stabilizer, are investigated as SERS-substrate. Each “flower” has large effective surface that is preserved at packing particles into a dense film and thus exhibits an advantageous property for SERS and similar sensing applications. The mycoextract used in our low-cost and green synthesis as surface stabilizer allows subsequent deposition of metal NPs or layers. One type of SERS substrates studied here was ZnO NPs decorated in situ in the solution by Ag NPs, another type was prepared by thermally evaporating Ag layer on the ZnO NP film on a substrate. A huge difference in the enhancement of the same analyte in the solution and in the dried form is found and discussed. Detection down to 10−7 M of standard dye analytes such as rhodamine 6G and methylene blue was achieved without additional optimization of the SERS substrates. The observed SERS-activity demonstrate the potential of both the free-standing flower-like ZnO NPs and thereof made dense films also for other applications where large surface area accessible for the external agent is crucial, such as catalysis or sensing.

Substrate-Selective Adhesion of Metal Nanoparticles to Graphene Devices.

Nanostructured electronic devices, such as those based on graphene, are typically grown on top of the insulator SiO2. Their exposure to a flux of small size-selected silver nanoparticles has revealed remarkably selective adhesion: the graphene channel can be made fully metallized, while the insulating substrate remains coverage-free. This conspicuous contrast derives from the low binding energy between the metal nanoparticles and a contaminant-free passivated silica surface. In addition to providing physical insight into nanoparticle adhesion, this effect may be of value in applications involving deposition of metallic layers on device working surfaces: it eliminates the need for masking the insulating region and the associated extensive and potentially deleterious pre- and postprocessing.

Tape of the truth: Ta2O5 nanopore array formed under broad potential range and SERS potential after silver sputtering

The deposition of a plasmonic metal layer on a nanostructured oxide surface is one of the important methods of preparing a platform for surface-enhanced Raman scattering (SERS) measurements. In this contribution, we describe the formation of SERS substrates by the deposition of a silver layer on ordered a Ta2O5 nanopore array. The influence of various experimental anodization process parameters on the morphology of a Ta2O5 nanopore array was carefully studied. It was found that the formation of a Ta2O5 nanopore array is possible under a broad potential range (15–50 V) in a highly acidic solution containing F− ions. In some cases, the nanopore array structures were covered by an outer layer rich in F− and SO42− ions, which could easily be removed using adhesive tape or by sonication. The deposition of an Ag layer led to SERS activity. The optimal Ag layer thickness was specified based on SEM and DRS measurements. The SERS substrates formed exhibited high point-to-point, sample-to-sample and time durability.

Study of the properties of the metal deposited with flux-cored wire of the Fe‒C‒Si‒Мn‒Сr‒W‒V system.

Alloys of the Fe‒C‒Si‒Мn‒Сr‒W‒V system widely used for hot-rolling roll repairs provide high resistance of the deposited layer against abrasion, but its thermal endurance is relatively low. It is shown that in order to ensure the quality of roll repair, it is necessary to improve the composition of the flux-cored wire charge and the technology of their use. It is proposed to reduce the structural heterogeneity of the deposited metal the use of flux-cored wire of the type PP-Np-35V9X3SF. The influence of the introduction of carbon-fluorinated elements and titanium on hydrogen concentration, microstructure, level of pollution by non-metallic inclusions, grain size, hardness and rate of wear of the deposited metal layer was evaluated. The data on the chemical composition of the deposited layer, the content of non-metallic inclusions in it, the microstructure of the deposited metal, depending on the content of titanium in the flux-cored wire, are presented. It was found that an increase the concentration of titanium increases the hardness of the deposited layer and reduces the rate of wear (abrasion) of samples. The effect on the level of contamination of the studied fused layers with oxide inclusions was not revealed. Increasing the hydrogen content in the deposited layer re-duces its hardness and increases the rate of wear of the deposited layer. Increasing the content of titanium in the depos-ited layer helps to reduce the size of the martensite needles, as well as the size of the former austenite grain. The de-pendencies of HRC hardness and wear resistance on the content of titanium and hydrogen in the deposited layer were established

Enhanced resistive switching of silver copper iodide thin films prepared by interfacial phase formation

Resistive random-access memory (ReRAM), an alternative to conventional charge storage memory, employs the switching of a resistive material between high-resistance and low-resistance states, which can be generated by the formation/dissolution of metal filaments bridging the two electrodes in the cell. Silver iodide (AgI) is a promising solid electrolyte for ReRAM cells, but its application is hindered by poor photostability and low electrical conductivity. Herein, a Cu-substituted β-AgI system, β′-Ag0.7Cu0.3I, was successfully prepared via sequential deposition of a Cu metal layer onto a AgI thin film by a galvanic reaction, which induced the spontaneous incorporation of Cu+ cations into the AgI lattice. Cu substitution at the Cu–AgI heterojunction interface is a novel way to modulate the chemical composition and improve the resistive switching properties of intrinsic polycrystalline AgI thin films. We compared the resistive switching properties of a ReRAM thin film devices based on β′-Ag0.7Cu0.3I with those based on pristine β-AgI. This device exhibited enhanced performance with high ON/OFF ratio (∼104) and low working voltage compared with the β-AgI-based device. These results strongly suggest that binary metal halide materials can serve as simple model systems for the efficient formation of metal filaments and have potential low-cost, low-power memory applications.

Straightforward Manufacturing of 3D-Printed Metallic Structures toward Customized Electrical Components.

Metalizing three-dimensional (3D)-printed polymers has been spotlighted in the field of manufacturing high-end and customized electrical components. Conventional metalization approaches that rely on the electroless plating (ELP) process typically require the use of noble metal-based catalysts or involve multistep processes, limiting their practical applications. Herein, we propose a straightforward yet effective approach to manufacture 3D-printed polymers with conductive metal layers through a thiol-mediated ELP process without involving an additional catalytic activation process. A photocurable ternary resin based on thiol-ene-acrylate monomers was precisely designed to induce excess thiol moieties on the surface of 3D-printed structures. These exposed thiol moieties served as active sites for metal ion complexion via strong metal-sulfur bonds, allowing the deposition of metal layers on the 3D-printed polymers through the ELP. Diverse metal layers, including Cu, Ag, and NiP, could be deposited onto virtually any 3D-printed structures with high uniformity and adhesion stability. To highlight the potential application of our approach, we fabricated fully functional glucose sensors through the deposition of the Cu layer on 3D-printed electrode models, and these sensors displayed excellent nonenzymatic glucose sensing performance. The proposed approach offers great insights for designing functional metallic structures and opens up new avenues for manufacturing lightweight, customized electrical components.

RESTORATION OF A STEAM TURBINE BLADE BY ARC WELDING WITH ORIENTATION OF ZONES OF INCREASED HARDNESS

Turbine blades are characterized by abrasive wear and erosion by solid particles. Features of wear of these elements are its rapid development and unevenness. The consequences of this are a decrease in spalling, a decrease in its cost-effectiveness, and a shortening of the inter-repair period. As a way to avoid uneven wear of the blade surface, it looks like the deposition of metal layers with the orientation of zones of increased hardness. From the literature data and the experience of previous studies, it is known about the positive effect of carbides on the wear resistance of the deposited metal. Taking into account the fact that the turbine blades are made of steels 30ХГСА, 20Х2, 10ХСНД, it was decided to investigate the effect of local preliminary application of carbides on surfacing with materials corresponding to these steels in composition. Surfacing was performed with Veltek-450 HG and Veltek H-50 wires with a diameter of 2 mm, as well as with Plan T-201 tape with a width of 10 mm and a thickness of 3.2 mm, using a UD-249 device in an argon environment. Titanium and boron carbide powders mixed with GF-021 primer were used as strengtheners. Through metallographic research, it was established that the most striking signs of dissolution of carbides are observed when surfacing with Veltek H-460G wire. From the point of view of the properties of the deposited layers, the combination of Veltek H-460G wire with B4C can be considered the most effective of those considered. This is due to the fact that the lower layer deposited with B4C application is more ductile (398 HB), and the upper one is harder (464 HB), which has a favorable effect on the occurrence of tensile stresses. Layers with the orientation of zones of increased hardness should be placed transversely to the movement of abrasive particles and the direction of crack development. It is expected that the arrangement of zones of greater hardness in this way will contribute to a decrease in the intensity of cracking. And zones of lower hardness, in turn, will restrain the development of cracks due to their greater plasticity.

Mirror-Assisted Radioluminescent Optical Fibers for X-Ray Beam Monitoring

In the framework of the current development of optical fiber sensors for dosimetry or beam monitoring applications based on radioluminescence (RL), we propose a method to enhance their radiation-induced light collection efficiency. This method consists in the deposition of a thin metallic layer, acting as a mirror, at the free output extremity of a radioluminescent optical fiber. Emitted visible photons guided in both directions along the optical fiber core can be collected by a single-ended detection system such as a photomultiplier tube. We characterize the impact of depositing two different types of metallic mirrors (Al and Au) on the performances of a RL based dosimeter, constituted by a Nitrogen-doped multimode optical fiber: its sensitivity has been calibrated with 40 keV X-rays at room temperature for dose rates from 0.05 to ~4 Gy(SiO <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sub> )/s. Also, investigation about the total ionizing dose effects on the mirror has been carried out to understand the evolution of the reflectance of the mirror under radiation exposure. This architecture of sensors appears as very promising, especially for the monitoring of low photon flux.

Synthesis and characterization of new low molecular weight aluminum organometallic complexes using amino/imine type ligands with possible uses in Atomic Layer Deposition processes

The driver of development and innovation in the microelectronics industry is the miniaturization of the components that make up each technological node. This miniaturization has given rise to new challenges for traditional materials and the need for new fabrication methods with sub-nanometer precision.Based on this, numerous methods have emerged for the fabrication of this type of nanometer materials, among which chemical deposition processes stand out. An industrial example of this type of chemistry is the so-called ALD (Atomic Layer Deposition), which generates deposition of nanometric metal layers, using precursors in a gaseous state.The use of metallic precursors in gaseous state, generates that the process has as a key factor the correct molecular design of the inorganic/organometallic material, since the method imposes strict requirements to the chemical and physical properties of these compounds, such as thermal stability, volatility, synthetic scaling, among others. With this in mind, in this research, new aluminum complexes were synthesized using TMA and imino/amine type ligands with low molecular weight substituents (isopropyl, tertbutyl), to generate stable and volatile liquid complexes in inert atmosphere at room temperature.Finally, four liquid complexes are obtained, stable in nitrogen atmosphere, with yields of 70%. Due to the mentioned characteristics, these complexes could be used as precursors for the deposition of Al and Al2O3 films. In addition, it is demonstrated that the use of TMA in this type of ligands can generate a methylation in the chain of this molecule, which opens a new field in the development of aluminum organometallic complexes.

Conductive carbon paint: An efficient way to electrodeposit metallic nanowires by using porous membranes

The present work demonstrates that conductive carbon paint, used for sample preparation in electron microscopy, can be a more straightforward and as-effective substitute for the metallic layer deposition usually used for the electrodeposition of metallic nanowires within porous membranes. AFM images demonstrated the good surface quality of the carbon layer. Raman spectroscopy confirmed the high crystallinity of carbon and high density of π-electrons. The electrical conductivity of the carbon layer was estimated using the linear sweep voltammetry technique. This new cathode was employed to grow continuous (Ni) and composition-modulated (Ni/Cu) nanowires within alumina templates, starting from aqueous solutions of Ni2+ and Cu2+ mixed salts. The obtention of metallic copper and nickel, and their separation can be readily observed by scanning electron microscopy and elemental mapping by EDS.