Metal Interface Research Articles

Coherent Control of Angular Interrogation of Sensitivity of the Surface Plasmon Polariton Waves at the Interface of Metal and Dielectric Medium

Coherent Control of Angular Interrogation of Sensitivity of the Surface Plasmon Polariton Waves at the Interface of Metal and Dielectric Medium

Microwave joining of copper pipes using selective microwave hybrid heating process: Simulation and experimental study

High thermal conductivity of copper poses serious challenges in its joining in conventional welding techniques leading to development of alternate welding techniques. Microwave welding is one such newly developed joining technique that use selective microwave hybrid heating (SMHH). The joining of the copper pipes using SMHH has not been explored in existing literature. The present paper attempts the microwave joining of copper pipes using SMHH. The exposure time required for joining copper pipes using SMHH was predicted by COMSOL Multiphysics software. The joining was attempted at the predicted exposure time using a novel cavity design inside a conventional microwave oven. The copper pipes have been successfully joined at temperature and exposure period of 1080ºC and 720 s respectively and was in good agreement with the predicted values i.e., 708 s. Scanning electron microscopy (SEM) revealed good metallurgical bonding between the base metal and joint interface. The presence of columnar grains has been observed at heat affected zone (HAZ) using electron back scattered diffraction (EBSD). EBSD analysis revealed randomly arranged grains with mixed modes of planes inside the base metal. The occurrence of high angle grains (HAGs) along with high dislocation density in base metal resulted in the improvement in the mechanical properties as revealed in grain average misorientation (GAM) maps. The maximum value of microhardness has been observed at the joint region (105 ± 7 Hv) followed by base metal and HAZ i.e. (97 ± 5 Hv) and (89 ± 8 Hv) respectively owing to the existence of fine grain of copper (µm) and carbide formation.

Operando monitoring of dendrite formation in lithium metal batteries via ultrasensitive tilted fiber Bragg grating sensors.

Lithium (Li) dendrite growth significantly deteriorates the performance and shortens the operation life of lithium metal batteries. Capturing the intricate dynamics of surface localized and rapid mass transport at the electrolyte-electrode interface of lithium metal is essential for the understanding of the dendrite growth process, and the evaluation of the solutions mitigating the dendrite growth issue. Here we demonstrate an approach based on an ultrasensitive tilted fiber Bragg grating (TFBG) sensor which is inserted close to the electrode surface in a working lithium metal battery, without disturbing its operation. Thanks to the superfine optical resonances of the TFBG, in situ and rapid monitoring of mass transport kinetics and lithium dendrite growth at the nanoscale interface of lithium anodes have been achieved. Reliable correlations between the performance of different natural/artificial solid electrolyte interphases (SEIs) and the time-resolved optical responses have been observed and quantified, enabling us to link the nanoscale ion and SEI behavior with the macroscopic battery performance. This new operando tool will provide additional capabilities for parametrization of the batteries' electrochemistry and help identify the optimal interphases of lithium metal batteries to enhance battery performance and its safety.

Rationally Designed Conversion‐Type Lithium Metal Protective Layer for All‐Solid‐State Lithium Metal Batteries

AbstractA stable interfacial design bridging Li metal and sulfide solid electrolytes is imperative for deploying practical all‐solid‐state Li metal batteries. Despite the extensive exploration of interlayer materials, including inorganic substances, lithiophilic metals, and their composites, a comprehensive understanding of their stability and chemo‐mechanical evolution, particularly those influenced by cell fabrication processes, remains unexplored. Herein, it is meticulously investigate the formation and evolution of LiF, Mg, and conversion‐type multicomponent MgF2 ultrathin interlayers, each fabricated via thermal evaporation deposition. Unexpectedly, LiF and Mg fail to enhance cell performance, with LiF notably susceptible to external pressures during cell fabrication, leading to serious current constriction, while Mg deposition results in the formation of a Li‐rich solid solution. Remarkably, the MgF2 coatings demonstrate substantially superior performance in both Li|Li6PS5Cl|Li symmetric cells (up to 2000 h) and LiNi0.70Co0.15Mn0.15O2|Li6PS5Cl|Li full‐cells (82% capacity retention after 800 cycles) at 30 °C. These results are attributed to the in‐situ formation of LiF and LixMg nanograins through a conversion reaction, which, after repeated cycling, maintains stability and a fixed position at the interface while ensuring uniform interfacial Li+ flux. Supported by comprehensive analyses, these findings highlight the pivotal role of conversion‐type interlayers in mitigating side reactions and preventing Li penetration.

Interfacial solvation-structure regulation for stable Li metal anode by a desolvation coating technique

Rechargeable lithium (Li) metal batteries face challenges in achieving stable cycling due to the instability of the solid electrolyte interphase (SEI). The Li-ion solvation structure and its desolvation process are crucial for the formation of a stable SEI on Li metal anodes and improving Li plating/stripping kinetics. This research introduces an interfacial desolvation coating technique to actively modulate the Li-ion solvation structure at the Li metal interface and regulate the participation of the electrolyte solvent in SEI formation. Through experimental investigations conducted using a carbonate electrolyte with limited compatibility to Li metal, the optimized desolvation coating layer, composed of 12-crown-4 ether-modified silica materials, selectively displaces strongly coordinating solvents while simultaneously enriching weakly coordinating fluorinated solvents at the Li metal/electrolyte interface. This selective desolvation and enrichment effect reduce solvent participation to SEI and thus facilitate the formation of a LiF-dominant SEI with greatly reduced organic species on the Li metal surface, as conclusively verified through various characterization techniques including XPS, quantitative NMR, operando NMR, cryo-TEM, EELS, and EDS. The interfacial desolvation coating technique enables excellent rate cycling stability (i.e., 1C) of the Li metal anode and prolonged cycling life of the Li||LiCoO2 pouch cell in the conventional carbonate electrolyte (E/C 2.6 g/Ah), with 80% capacity retention after 333 cycles.

Microstructure – Properties relationship in laser-welded AZ31B magnesium alloy

The AZ31B magnesium alloy was laser-welded at three different (1.2, 1.6, and 2 kW) laser output powers in the present work. All the butt weld joints are almost defect-free. The size of the weld joint slightly increases with increasing laser output power. The weld metal is formed by columnar grains of the alpha phase at the weld metal/base metal interface, but a finely equiaxed grain microstructure is formed in the centres of fusion zones. The minor phases are Mg17Al12 and (Al,Mg)8Mn5. The weld metal microstructure manifests clear refinement with a decrease in laser output power. Microstructural changes are reflected in changes in mechanical properties; weld joints prepared at the lowest laser output power manifest the highest microhardness, ultimate tensile strength, yield strength, and almost 90% joint efficiency. This is related to the different extents of strengthening mechanisms that act most effectively in weld joints made at 1.2 kW laser output power. Detail analysis of fracture surfaces confirmed that lower laser output power and general microstructural refinement favours the formation of plastically deformed material, which is in excellent agreement with both the experimentally determined and the calculated values of yield strength.

Effect of carbon black and curing system on rubber–metal interface strength of automotive components

Rubber–metal parts inside the car require rubber compounds capable of ensuring optimal function and maximum service life without interface delamination. From this perspective, the strength of the bond which is created by the chemical interaction of rubber and metal by an adhesive is decisive for ensuring the functionality of the entire compound. It is dependent not only on the choice of the right adhesive but also on the rubber compound ingredients and their amount. Here, the influence of different types of carbon blacks as well as different curing systems in combination with a commonly used adhesive is described. The durability of the metal–adhesive–rubber bond is characterized by a specially designed shear strength analysis under quasi-static loading, whereas a significant influence of the structure of the carbon black has shown. It has also been observed that the presence of monosulphidic bonds has a positive effect on the shear strength.

Ultraclean Interface of Metal Chalcogenides with Metal through Confined Interfacial Chalcogenization.

Acquisition of defect-free transition metal dichalcogenides (TMDs) channels with clean heterojunctions is a critical issue in the production of TMD-based functional electronic devices. Conventional approaches have transferred TMD onto a target substrate, and then apply the typical device fabrication processes. Unfortunately, those processes cause physical and chemical defects in the TMD channels. Here, a novel synthetic process of TMD thin films, named confined interfacial chalcogenization (CIC) is proposed. In the proposed synthesis, a uniform TMDlayer is created at the Au/transition metal (TM) interface by diffusion of chalcogen through the upperAu layer and the reaction of chalcogen with the underlying TM. CIC allows for ultraclean heterojunctions with the metals, synthesis of various homo- and hetero-structured TMDs, and in situ TMD channel formation in the last stage of device fabrication. The mechanism of TMD growth is revealed by the TM-accelerated chalcogen diffusion, epitaxial growth of TMD on Au(111). We demonstrated a wafer-scale TMD-based vertical memristors which exhibit excellent statistical concordance in device performance enabled by the ultraclean heterojunctions and superior uniformity in thickness. CIC proposed in this study represents a breakthrough in in TMD-based electronic device fabrication and marking a substantial step toward practical next-generation integrated electronics.

Deciphering the Interplay between Local and Global Dynamics of Anodic Metal Oxidation.

The stark difference between global and local metal oxidation dynamics underscores the need for methodologies capable of performing precise sub-μm-scale and wide-field measurements. In this study, we present reflective microscopy as a tool developed to address this challenge, illustrated by the example of chronoamperometric Fe oxidation in a NaCl solution. Analysis at a local scale of 10 s of μm has revealed three distinct periods of Fe oxidation: the initial covering of the metal interface with a surface film, followed by the electrochemical conversion of the formed surface film, and finally, the in-depth oxidation of Fe. In addition, thermodynamic calculations and the quantitative analysis of changes in optical signal (light intensity), correlated with variations in refractive indexes, suggest the initial formation of maghemite, followed by its subsequent conversion to magnetite. The reactivity maps for all three periods are heterogeneous, which can be attributed to the preferential oxidation of certain crystallographic grains. Notably, at the global scale of 100 s of μm, reactivity initiates at the electrode border and progresses toward its center, demonstrating a unique pattern that is independent of the local metal structure. This finding underscores the significance of simultaneously employing sub-μm-precise, quantitative, and wide-field measurements for a comprehensive description of metal oxidation processes.

Stabilization the interface of NASICON-type solid electrolyte and Li metal by Al interlayer

Solid-state lithium-ion batteries with intrinsic safety and stable performance have emerged as alternative to liquid electrolyte-based systems. NASICON-type Li1.3Al0.3Ti1.7(PO4)3 (LATP) with high ionic conductivity is a promising solid electrolyte to be commercialized. However, the incompatibility of LATP with Li metal hinders its application in high energy density solid-state systems. Herein, we apply a 60 nm thick protective Al layer by PVD to construct a stable interface with metallic Li. The Al-coated LATP enables better electrochemical performance in a symmetric cell than bare LATP. Al-coated LATP is stable at 0.1 mA cm−2 for 100 cycles without building up polarization. The overpotential and the interfacial resistance are significantly reduced as direct contact between Li and LATP is avoided. The Al coating inhibits the reduction of Ti4+ to Ti3+ of LATP pellet during cycling. This work resolves the prominent limitations of LATP and strengthens the interfacial connectivity in solid-state system, pointing an environmental friendly and low cost modification strategy to improve the solid-state lithium-ion batteries.

Optimized film thicknesses for maximum refractive index sensitivity and figure of merit of a bimetallic film surface plasmon resonance sensor

In this paper, a simple surface plasmon resonance (SPR) optical sensor with a bimetallic gold-silver film is proposed and its parameters are optimized based on reflectance spectra analysis. In comparison with most SPR sensors, which use single gold films, the evanescent field of this bimetallic configuration at the analyte–metal interface enables the sensing with substantially enhanced refractive index (RI) sensitivity and figure of merit (FOM). The proposed structure comprising a BK7 glass substrate, an adhesion layer of chromium, a gold-silver plasmonic layer, and a protective layer of silicon dioxide is employed in the Kretschmann configuration for liquid analyte sensing. In order to achieve the best sensing properties, the gold-silver layer thickness ratio is varied, and a thorough analysis of reflectance spectra is performed based on RI sensitivity and FOM. For this purpose, a liquid analyte of aqueous solutions of NaCl is employed for angles of incidence 63∘\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$$^\\circ $$\\end{document} and 64∘\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$$^\\circ $$\\end{document}, respectively. Moreover, based on the analysis, an optimized gold-silver layer thickness ratio is selected, and a sensitivity of 41,592 nm per RI unit (RIU) and FOM of 424 RIU-1\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$$^{-1}$$\\end{document} are reached. The designed bimetallic SPR structure proves to be advantageous compared to single-gold-film structures employed for sensing applications.

Effect of carbon content and cooling rate on the microstructure and hardness of TiC-Fe-Cr-Mo cermets

TiC-FeCrMo cermets have been obtained in fully dense form by Sinter HIP at 1400 °C. Significant microstructural changes have been observed in these materials for relatively small variations in their carbon content after sintering. In the cermets with higher carbon content Cr-rich likely M7C3 carbides are observed to precipitate at the (Ti1-x,Mox)yCz - metal interface. In addition, these cermets present a significant amount of retained austenite as part of the metal matrix. No retained austenite and many fewer M7C3 carbides are found in alloys with a reduction of 0.2 wt% in the total C content. Continuous cooling diagrams have been obtained from an austenitizing temperature of 950 °C. Hardness increases by 30% with respect to that of as sintered specimens after cooling at 1 °C/s confirming that these TiC-FeCrMo cermets are suitable for hardening by air-quenching. At this cooling rate, it is observed that the relatively small carbon changes mentioned before have a significant effect on the bainitic transformation, displacing its onset to higher temperatures as the C content is reduced. Slower cooling rates result in complex microstructures, in which, in addition to martensite, ferritic bainite, M7C3 and M23C6 carbides are also found. Microstructure and hardness of TiC-FeCrMo materials can be modified by the use of standard heat treatments to obtain a wide variety of mechanical properties suitable for certain hot rolling applications.

Investigations of Al-Manufacturing while 7075/RHA/Al2O3 Composite by Squeeze Casting Approach"

The superior performance. metal matrix nano-composite substance containing agro-waste reinforcements is the subject of this study's manufacturing and characterization efforts. Composites made using aluminum 7075 as their basis substance with reinforced with rice husk ash (RHA) and Al2O3 are very desirable. The revolutionary composite was made using squeeze casting as the fabrication technique. The overall size % of ash from rice husks on its metal interface was adjusted from 0% to 15% with a constant increase of 5%, while the Al2O3 percentage was set at 3. Many qualities, including hardness, toughness, tensile strength, XRD analysis, XDS analysis, Surface Morphology and wear, define the manufactured composite. According to the findings, the produced cost-effective composite outperforms the raw material in terms of hardness, toughness, and tensile strength.

Interface of gallium-based liquid metals: oxide skin, wetting, and applications.

Gallium-based liquid metals (GaLMs) are promising for a variety of applications-especially as a component material for soft devices-due to their fluidic nature, low toxicity and reactivity, and high electrical and thermal conductivity comparable to solid counterparts. Understanding the interfacial properties and behaviors of GaLMs in different environments is crucial for most applications. When exposed to air or water, GaLMs form a gallium oxide layer with nanoscale thickness. This "oxide nano-skin" passivates the metal surface and allows for the formation of stable microstructures and films despite the high-surface tension of liquid metal. The oxide skin easily adheres to most smooth surfaces. While it enables effective printing and patterning of the GaLMs, it can also make the metals challenging to handle because it adheres to most surfaces. The oxide also affects the interfacial electrical resistance of the metals. Its formation, thickness, and composition can be chemically or electrochemically controlled, altering the physical, chemical, and electrical properties of the metal interface. Without the oxide, GaLMs wet metallic surfaces but do not wet non-metallic substrates such as polymers. The topography of the underlying surface further influences the wetting characteristics of the metals. This review outlines the interfacial attributes of GaLMs in air, water, and other environments and discusses relevant applications based on interfacial engineering. The effect of surface topography on the wetting behaviors of the GaLMs is also discussed. Finally, we suggest important research topics for a better understanding of the GaLMs interface.

NiCrO/MCu111 interface sites for synergistic catalysis of water splitting

Oxide–metal interface sites with multimetallic composition and the tuned electronic structure achieving outstanding HER activity.

NBis(2-hydroxyethyl) ammonium dodecanoate and its constituents as inhibitors for Al corrosion and H2 production in acid medium

2-(2-Hydroxyethylamino) ethanol (EA), dodecanoic acid (DA), and a freshly prepared ionic liquid named bis(2-hydroxyethyl) ammonium dodecanoate (ADD) were exercised as mitigators towards the corrosion of aluminum and the production of hydrogen in 2.0 M HCl. The study was performed by gravimetry, gasometry, potential-time measurements, and electrochemical methods. The examined concentration range of such inhibitors was varied between 5 × 10-6 M and 5 × 10-3 M. The amount of generated hydrogen is enhanced with temperature and lowered by increasing the concentration of the organic additive. Galvanostatic studies indicated that the utilized organic materials are effective inhibitors of a mixed type. The inhibition efficacy was found to increase with more additions of inhibitors and is lowered by temperature. ADD is the more effective inhibitor with a protective efficacy of 95.2% at 0.005 M and 298 K. The computed values of ΔGoads vary between – 35.48 and − 35.00 kJ/mol depending on the type of the organic compound and temperature that confirms the existence of a physical adsorption mechanism. The lowering in the Kads values with T confirms the escaping of several adsorbed organic particles from the contact metal interface. The thermodynamic adsorption functions, ΔG°ads, and Kads confirmed the spontaneous adsorption process, i.e., physical- and chemisorption mechanisms.

Improving bonding strength of W/Cu dual metal interface through laser micro-structuring method

Improving bonding strength of W/Cu dual metal interface through laser micro-structuring method

Formation characteristics and acoustic regulation of liquid metal droplets in low-aspect-ratio channels

The uniformity in size of liquid metal droplets is crucial in determining the accuracy of flexible circuit printing as well as the stability in signal transmission. In this study, the numerical simulation and the experiment method are combined to analyze the droplet preparation process of liquid metal. Furthermore, the mechanism of the surface acoustic wave as an external force dominating the breakup of the liquid metal interface is investigated. The results show that the squeezing pressure and the capillary force are the dominant forces of the interface evolution in the low-aspect-ratio (height/width) channel. When the dispersed phase flow rate is low, the interface will retract upstream of the channel under the influence of large interfacial tension after breakup, resulting in fluctuations in flow rate, and therefore, the stability of droplet size is weak. When the dispersed phase flow rate is high, the interface randomly breaks up under the influence of the Rayleigh–Plateau instability, which also leads to uneven droplet size. As the acoustic intensity increases, the acoustic radiation pressure gradually becomes the dominant force responsible for the squeezing and breakup of the interface. It increases the radial contraction rate of the interface, shortens the droplet generation period, and ultimately reduces the droplet size. Additionally, the size deviation value is significantly reduced from 10.13% to 1.05%. This study is useful in elucidating the evolution mechanism of liquid metal interfaces in low-aspect-ratio channels, improving the fundamental theory of interface breakup caused by acoustic radiation pressure, and providing theoretical guidance for the controlled and stable production of liquid metal droplets.

Metal to insulator transition for conducting polymers in plasmonic nanogaps

Conjugated polymers are promising material candidates for many future applications in flexible displays, organic circuits, and sensors. Their performance is strongly affected by their structural conformation including both electrical and optical anisotropy. Particularly for thin layers or close to crucial interfaces, there are few methods to track their organization and functional behaviors. Here we present a platform based on plasmonic nanogaps that can assess the chemical structure and orientation of conjugated polymers down to sub-10 nm thickness using light. We focus on a representative conjugated polymer, poly(3,4-ethylenedioxythiophene) (PEDOT), of varying thickness (2-20 nm) while it undergoes redox in situ. This allows dynamic switching of the plasmonic gap spacer through a metal-insulator transition. Both dark-field (DF) and surface-enhanced Raman scattering (SERS) spectra track the optical anisotropy and orientation of polymer chains close to a metallic interface. Moreover, we demonstrate how this influences both optical and redox switching for nanothick PEDOT devices.

Ultrafast Plasmonics for All-Optical Switching and Pulsed Lasers

Surface plasmon resonances (SPRs) are often regarded as the collective oscillations of charge carriers localized at the dielectric–metal interface that display an ultrafast response upon light excitation. The recent developments in the fabrication and characterization of plasmonic nanostructures have stimulated continuous effects in the search for their potential applications in the photonic fields. Concentrating on the role of plasmonics in photonics, this review covers recent advances in ultrafast plasmonic materials with a prime focus on all-optical switching. Fundamental phenomena of plasmonic light–matter interaction and plasmon dynamics are discussed by elaborating on the ultrafast processes unraveled by both experimental and theoretical methods, along with a comprehensive illustration of leveraging ultrafast plasmonics for all-optical switching and pulse laser generation with a focus on device design and performance. This review is concluded with a brief highlight of the current progress and the potential future directions in ultrafast plasmonics.