Diffusion Of Silver Research Articles

Kinetics of thermal and photoinduced diffusion of Ag into thin layers of chalcogenide glasses

This study examines the kinetics of thermal diffusion of silver in Ag-GeSe2 and Ag- As10Ge30S60 thin film structures during prolonged storage in the dark at room temperature, as well as the effects of plasmon-enhanced photostimulated diffusion of silver into As10Ge30S60 films. Ag diffraction gratings with a period of 519 nm were used to excite surface plasmon-polaritons (SPP) at the silver-chalcogenide glass interface. It was found that the thermal diffusion coefficient of silver into GeSe2 is significantly higher than into As10Ge30S60. For Ag– As10Ge30S60, photostimulated silver diffusion coefficients were measured with and without SPP excitation. SPP excitation triples the photostimulated Ag flux into As10Ge30S60. Although photosensitivity decreases over time, the plasmon-stimulated increase in Ag flux remains stable. Additionally, As10Ge30S60 thermally doped with silver shows much higher optical absorption at the probing wavelength compared to the photodoped layer with the same silver concentration. Possible mechanisms of these layers formation are discussed.

Preparation and characterization of Ea-AgNPs-Si nanocomposite: investigating it as a poultry reformer, pathogen suppressor, sprouting catalyst and adsorbent

This study synthesizes nano composite (Ea-AgNPs-Si) using Euphorbia antisyphilitica(Ea), employing it as a poultry reformer, sorptive material, pathogen suppressor and sprouting catalyst. Characterization involved XRD, SEM, TEM, Zetasizer, UV-Visible and FT-IR techniques. Ea-AgNPs-Si adopted a face centered cubic arrangement with average crystalline size of 20.34 nm. Zeta potential assessed stability. PDI value of Ea-AgNPs-Si nanocomposite is 1 indicating the polydisperse distribution. SEM revealed flower shape (Ea-AgNPs-Si), ranging 70-100 nm in diameter. The disc diffusion method reveals that EaAgNPs-Si exhibits potent antimicrobial activity at 60 µl against Staphylococcus aureus, Actinomycetes, Escherichia coli, Klebsiella pneumonia and Pseudomonas aeruginosa, attributed to its deep diffusion and release of silver ions and silica. It is unequivocally evident from the data that Langmuir isotherm and Pseudo II order model provides a superior fit approaching R2 value as 0.9972, 0.9461, 0.916, 0.9827, 0.9455 and 0.9534 for LA(I), LA(II), LA(III) describing monolayer chemisorption onto surfaces with uniform adsorption energies than Freundlich, Tempkin and BET models, which is synonymous with the results obtained from R2011a Matlab neuro solution. Through final germination (FG) we concluded that among 130 corriandrum seeds sown,109 sprouted in 20 days. Higher germination index (GI) T2>T4>T1>T3> expedited that Ea-AgNPs-Si shall be used as a nutrient to boost the growth of crops. Ordinarily, it necessitates a span of 45 days for a single batch to attain harvest readiness; however, through our efforts, we have accomplished this feat in a mere 20 days. Henceforth, Ea-AgNPs-Si shall be employed as a Poultry Reformer, Pathogen Suppressor, Sprouting Catalyst and Adsorbent.

Preparation of high-performance multilayer circuits by controlling the diffusion of Ag in borosilicate glass-ceramics through the addition of SiO2

Due to its superior reliability and performance, thick film technology is extensively employed in various applications, including automotive electronics, consumer electronics, communication engineering, and aerospace. However, a challenge arises from the mutual diffusion during the electronic paste production process, which leads to a decline in insulation performance and hinders the production of three-dimensional equipment. Inspired by the principles of low-temperature co-fired ceramic technology, a multi-layered ceramic structure has been successfully bonded using thick film technology by introducing a borosilicate glass-ceramics layer. To further enhance the properties of this multi-layered ceramic structure, approximately 8 wt% SiO2 was incorporated into the borosilicate glass-ceramics. This addition effectively inhibits silver diffusion and reduces the diffusion depth within the glass-ceramic film. The key mechanisms behind this improvement are the increased activation energy for crystallization, resulting in a slower crystallization rate due to the addition of SiO2. Moreover, the multi-layered ceramic with a sandwich structure exhibits remarkable properties. Notably, the dielectric strength of this system has been significantly enhanced to 13.9 kV/mm, accompanied by a high adhesion strength of 790 N. These enhanced properties of the optimized system indicate promising characteristics for multi-layer circuit applications.

Insights on the effect of process conditions on the optical properties of silver ion exchanged soda-lime silicate glass

The effects of ion exchange time and temperature on the optical properties and plasmonic response of silver ion exchanged soda-lime silicate glass were investigated using scanning electron microscopy (SEM) in energy dispersive spectrometry (EDS) configuration, m-lines spectroscopy, photoluminescence (PL) spectroscopy, and UV–visible absorption spectroscopy. SEM analyses in EDS mode provided profiles of silver oxide molar concentration. These profiles were directly correlated to the silver diffusion coefficient using an adjustment procedure. The effective indices of ion exchanged glasses measured by the standard prism coupling technique (m-lines) allowed access to refractive index distributions in ion exchange regions. These ion-exchanged glasses underwent evaluation to determine their potential suitability for use in multimode planar systems. The PL results acquired after ion exchange demonstrated that the creation of Ag0 atoms from Ag+ ions was responsible for the decline and quenching of PL intensity at ion exchange times and temperatures increase. Silver nanoparticles were generated in the samples subjected to ion exchange at 480 °C without the need for post-exchange treatments. The emergence of the surface plasmon resonance band around 427 nm in the optical absorption spectra confirmed the formation of Ag nanoparticles in annealed glasses. Estimates of the UV–visible absorption spectra indicated an average size of silver nanoparticles ranging from 1.8 to 2.4 nm.

Electrochemical synthesis of 2D-silver nanodendrites functionalized with cyclodextrin for SERS-based detection of herbicide MCPA

Surface enhanced Raman spectroscopy (SERS) is a powerful analytical technique that has found application in the trace detection of a wide range of contaminants. In this paper, we report on the fabrication of 2D silver nanodendrites, on silicon chips, synthesized by electrochemical reduction of AgNO3 at microelectrodes. The formation of nanodendrites is tentatively explained in terms of electromigration and diffusion of silver ions. Electrochemical characterization suggests that the nanodendrites do not stay electrically connected to the microelectrode. The substrates show SERS activity with an enhancement factor on the order of 106. Density functional theory simulations were carried out to investigate the suitability of the fabricated substrate for pesticide monitoring. These substrates can be functionalized with cyclodextrin macro molecules to help with the detection of molecules with low affinity with silver surfaces. A proof of concept is demonstrated with the detection of the herbicide 2-methyl-4-chlorophenoxyacetic acid (MCPA).

Thermal Sintering Matchability between Low‐Temperature Cofired Ceramic Substrate and Silver Pastes and the Effect of CuO on Silver Diffusion Inhibition

Low‐temperature cofired ceramic (LTCC) materials are a promising material for heat dissipation substrates due to their excellent thermal conductivity and thermal expansion coefficient similar to that of silicon. However, the difficulties in surface metallization techniques limit its application. This work uses Bi–B–Si–Zn–Al glass/ceramic composite as the substrate and Bi–B–Si–Zn–Al glass powder as the inorganic binder for silver pastes. The silver thick film with a glass content of 3 wt% is sintered at 800 °C for 30 min, and the samples have excellent electrical conductivity (surface square resistance of 0.29 mΩ £−1) and mechanical properties (interface bonding force of 17.56 MPa). In addition, the introduction of CuO into the glass phase can inhibit the silver diffusion phenomenon during the sintering process and improve the conductive performance of the material. The results are beneficial for the preparation and application stability of LTCC devices.

Plasmon enhancement of photosensitivity of Ag–chalcogenide glass thin film structures

In this paper, we present the results of studying the features of plasmon- enhanced photostimulated diffusion of silver into thin films of chalcogenide glasses (ChG), in particular, As 2 S 3 and GeSe 2 . To ensure excitation of surface plasmon-polaritons (SPPs) at the interface between silver and ChG films, silver diffraction gratings with periods of 899 and 694 nm were used as substrates. The samples were exposed to the p-polarized radiation of a He-Ne laser (λ = 632.8 nm). The radiation of the same laser, attenuated by two orders of magnitude, was used to detect SPP, which enabled to study the kinetics of photostimulated processes in the thin-layer structure of Ag–ChG. It has been established that in the initial period of exposure, the SPP electromagnetic field significantly enhances the photostimulated flux of silver ions in ChG (by 2-3 times). The photodissolution kinetics of Ag in ChG is defined by the features of the granular structure of the investigated thin chalcogenide films. For the GeSe 2 film with the effective thickness 8 nm, the kinetics of the film refractive index increase caused by silver photodoping is well approximated by a logarithmic dependence. For the Ag–As 2 S 3 structure (the effective thickness of the As 2 S 3 film is 14.8 nm), this kinetics is closer to the linear one; moreover, for photodoping without SPP excitation, the kinetics is somewhat superlinear, while with plasmon excitation, it is sublinear. The main physical mechanism responsible for the acceleration of the process of photostimulated diffusion in the structure under study appears to be an accelerated generation of electron-hole pairs, which takes place in the ChG layer near the interface with the metal, where the SPP electromagnetic field strength is maximum, and/or plasmon- assisted hot carrier generation due to plasmon scattering on the surface of the metal film and subsequent internal photoemission of electrons from silver into chalcogenide.

Bipolar and rectifying resistive switching dynamics in E-beam evaporated SnOx based memristor

In this article, we have examined the crystallinity and semiconducting properties (n-type and/or p-type) of e-beam evaporated Tin-oxide (SnOx) with different deposition substrate temperature and study their impact over resistive switching dynamics with Silver (Ag) active and Platinum (Pt) inert metal electrode. The fabricated Resistive switching (RS) devices have performed forming free bipolar and rectifying resistive switching with n-type and p-type semiconducting properties of deposited insulating layer, respectively. The crystal structure and elemental composition of deposited insulating layers (SnOx) have been characterized by using Glancing Angel X-Ray Diffraction (GAXRD) and Energy Dispersive X-Ray (EDX). The electrical responses of fabricated RS devices have been observed by using Keithley-4200 parametric analyser with customize probe station and performance of the bipolar and rectifying RS devices have been analysed with low sweeping voltage (−1.5V/1.5V) along with 20 K pulsative endurance at RT and 105 s retention at 85 °C. We have also described the diffusivity of Silver (Ag) active metal electrode into deposited insulating layers and physics behind BRS and RRS dynamics in fabricated device.

Microstructural evolution during low-temperature brazing of WC-Co cemented carbide to AISI 4140 steel using a silver-based filler alloy

The joining of cemented carbides to steels used in the drilling/excavation industries due to their distinct characteristics has posed a significant challenge. This research systematically investigates the effect of brazing temperature (650, 700, and 750 °C) and time (5, 10, and 15 min) as the most effective brazing parameters on the phase transformations and interfacial microstructure of WC-Co/AISI 4140 steel joints. Low-temperature brazing due to eliminating the destructive η carbides at the cermet interface, makes it a more appropriate procedure, as compared to fusion-welding methods, as per the findings of the current study. It was revealed that the optimal condition for the process is at 650 °C for a duration of 10 min, in which the eutectic structure is refined and the distribution of primary dendrites is uniform. The microstructure of the brazed area presents a multiphase structure, comprised of a copper-rich solid solution (Cu,Zn), a silver-rich solid solution (Ag,Cd), a eutectic structure as well as the β′-CuZn ordered phase. The β embedded in ternary eutectic structure was partially transformed to β′ during the cooling cycle of the brazing process. Diffusion of silver and cadmium in cemented carbide, as well as the formation of Co-Fe-Cu reaction product, were proposed as the bonding mechanisms. The effectiveness of brazing temperature in enlarging the cobalt-depleted zone appearing in WC-Co is comparatively higher than that of brazing time. It is also concluded that by increasing the brazing temperature and duration, the fraction of copper solid-solution dendrites distributed in the joint area decreases, however, the size increases.

Plasmon-enhanced photostimulated diffusion in a thin-layer Ag–GeSe2 structure

This work studies photostimulated diffusion of silver, enhanced by a plasmon field, into GeSe2 thin films. To ensure the excitation of surface plasmon polaritons (SPP) at the interface between Ag and GeSe2, silver diffraction gratings substrates were used, on which chalcogenide layers were deposited by thermal evaporation in vacuum. The samples were exposed to the p-polarized radiation of a He-Ne laser. The kinetics of photostimulated processes was studied by recording the changes in SPP characteristics with exposure. It has been established that at the initial stage of the photodiffusion process, SPP excitation at the Ag/GeSe2 interface during exposure results in a fourfold increase in the photostimulated flux of silver ions. The concentrations of photodissolved silver in the chalcogenide layer are estimated. The mechanism of photostimulated diffusion of Ag in GeSe2 and its features in such thin-layer structures, as well as a possible mechanism of plasmon-stimulated acceleration of this process, is discussed.

The role of interfaces and morphology on silver diffusion in hard coatings

One of the main approaches to increase the tool lifetime during dry machining of “hard-to-machine” aerospace alloys is self-lubrication by the incorporation of noble metals in hard matrixes with good mechanical and diffusion barrier properties. In this paper, the diffusion of an Ag-rich layer sandwiched between two layers of either TiN or TiSiN is studied by transmission electron microscopy and in situ Rutherford backscattering spectrometry. The layer stacks were subjected to annealing treatments at 600 °C and 800 °C for 2 hours. Three processes were found to control the diffusion of silver: the morphology of the “sandwich” layers, the formation of small voids in the involved interfaces and the sublimation of Ag in the surface at temperatures near the melting point. The study revealed that the dense TiSiN matrix allowed a significantly better control of Ag diffusion than the more open TiN matrix.

Low-resistance joints for YBCO-coated conductors with Ag nanoparticle paste

Due to the limited available piece length of YBCO-coated conductors (i.e. tapes or wires) and the different requirements for magnetic field, joints are inevitable for manufacturing high-temperature superconducting magnets. In this study, a sintering nano-silver (Ag) process was developed and used to connect YBCO tapes stabilized by anAg layer with low-temperature and short-time sintering of Ag nanoparticle (NP) paste. The thermodynamic characteristics of Ag NP paste were explored using a TG/DSC setup. The effects of sintering temperature, mechanical pressure and lapped length on microstructures and electrical properties of joints were comprehensively investigated. It is found that the pre-volatilization of low-boiling-point solvent in the paste is beneficial to improve the densification of sintered structure, thus contributing to increasing the critical current I c of the joint. With increasing sintering temperature, the I c of the joint will be close to that of the virgin tape, and the joint resistance experiences small fluctuations, but joint connectivity is enhanced. As the temperature reaches 205 °C, I c decreases to 84% of the virgin tape, and joint resistance increases obviously. In addition, the axial tension strength at room temperature is improved with the increase in mechanical pressure, while the resistance does not demonstrate distinct variation. Considering the electromechanical properties, the optimal joining process is determined as sintering at 180 °C and 30 MPa for 10 min. The joint with this technology possesses a closely connected interface and a well-sintered nano-Ag microstructure with pores. By further extending the lapped length, a YBCO joint resistivity as low as ∼10.56 nΩ cm2 is obtained, which is around a quarter of that of the soldering joint, and the process is much easier than that of the Ag diffusion joint.

Fabrication of high-quality joints between Gd–Ba–Cu–O bulk superconductors

This work reports a technique for fabricating superconducting joints between GdBCO-Ag bulk superconductors, using YBCO-Ag as an intermediate joining material. The ability to provide reliable joints between multiple bulk superconductors overcomes many of the challenges of fabricating large superconductors or machining hard and brittle bulk superconductors into practical shapes. We report on nine single grains of GdBCO-Ag which have been joined with a YBCO-Ag intermediate. Samples were cut and joined in a variety of c-plane orientations to refine and understand the effect this had on the superconducting properties of jointed samples. The trapped field of pre-jointed and jointed bulk superconductors were compared; the maximum trapped field achieved was 59% of the pre-jointed sample. Further analysis showed that the critical temperature and critical current of the samples were degraded by the jointing process. Microstructural and chemical analysis showed that the jointing process facilitated diffusion of silver towards the joint and in some cases large pores were formed at the joint interface. These factors consequently inhibited current flow across the joint and thus reduced the maximum trapped field achievable when compared to the original unjointed sample.

Diffusion of Silver in Liquid Tin Depending on the Temperature Gradient Along the Solder in Low-Voltage Power Fuses at Overcurrents

Diffusion of Silver in Liquid Tin Depending on the Temperature Gradient Along the Solder in Low-Voltage Power Fuses at Overcurrents

Low temperature sintering lead‐free dielectric xBiScO3‐(1‐x)BaTiO3 for energy storage applications

AbstractFabrication of ceramic capacitors requires technological breakthroughs to address growing concerns regarding sustainability, cost, and increased power consumption in the manufacturing process. Low temperature sintered xBiScO3‐(1‐x)BaTiO3 (BS‐BT) with x = 0.4 is found to possess excellent energy storage performance and temperature stability. The grain size decreases from 3.5 μm sintered at 1100°C to less than 0.5 μm sintered at 800°C, leading to much improved breakdown field and energy storage properties. Recoverable energy density of 4.7 J/cm3 with a high efficiency of 89% was obtained at an electric field of 390 kV/cm, showing an excellent temperature stability over temperature range of 25–200°C and fatigue endurance for more than 105 cycles. Of particular importance is that the ceramic tape cofired with silver electrode over temperature range of 800–850°C shows no reaction and diffusion of silver at the electrode/ceramic interface, while a recoverable energy density of 3.3 J/cm3 was achieved with satisfactory efficiency of 80% at an electric field of 340 kV/cm when sintered in reduced atmosphere, expanding the electrode selection to low‐cost base metal, such as Cu and Ni. This work provides a good paradigm in ceramic capacitor fabrications that will help reduce overall cost and power consumption by utilizing low temperature sintered lead‐free dielectrics with comparable or even superior energy storage properties over state‐of‐the‐art dielectrics.image

SILVER-COATED CUSTOM COMPONENTS FOR ACETABULAR AND HEMIPELVIS RECONSTRUCTION MITIGATE INFECTION RISK WITHOUT COMPROMISING BONE ONGROWTH

Complex acetabular reconstruction for oncology and bone loss are challenging for surgeons due to their often hostile biological and mechanical environments. Titrating concentrations of silver ions on implants and alternative modes of delivery allow surgeons to exploit anti-infective properties without compromising bone on growth and thus providing a long-term stable fixation. We present a case series of 12 custom acetabular tri-flange and custom hemipelvis reconstructions (Ossis, Christchurch, New Zealand), with an ultrathin plasma coating of silver particles embedded between layers of siloxane (BioGate HyProtect™, Nuremberg, Germany).At the time of reporting no implant has been revised and no patient has required a hospital admission or debridement for a deep surgical site infection. Routine follow up x-rays were reviewed and found 2 cases with loosening, both at their respective anterior fixation. Radiographs of both cases show remodelling at the ilium indicative of stable fixation posteriorly. Both patients remain asymptomatic. 3 patients were readmitted for dislocations, 1 of whom had 5 dislocations within 3 weeks post-operatively and was immobilised in an abduction brace to address a lack of muscle tone and has not had a revision of their components.Utilising navigation with meticulous implant design and construction; augmented with an ultrathin plasma coating of silver particles embedded between layers of siloxane with controlled and long-term generation of silver ion diffusion has led to outstanding outcomes in this series of 12 custom acetabular and hemipelvis reconstructions. No patients were revised for infection and no patients show signs of failure of bone on growth and incorporation. Hip instability remains a problem in these challenging mechanical environments and we continue to reassess our approach to this multifaceted problem.

Molecular Dynamics Study of Structural and Transport Properties of Silver Iodide Using Effective Charges.

The superionic conductor, solid state, and body-centered cubic structure, silver iodide at room temperature, has been studied via molecular dynamics simulations. The calculated results using pairwise Coulomb-Buckingham potential, zero pressure on the sample, a semi-rigid model system of 1000 Ag and 1000 I ions, () as a statistical ensemble, and an effective charge of for the pairs Ag-Ag and I-I, were found to be consistent with experimental data and one study using , different potential, and simulation software. For the pair Ag-I, there is a discrepancy due to the high silver ion diffusion. The calculated value of the diffusion constant of the silver ion is greater than iodide ion. The dynamic transport properties (mean square displacement, velocity autocorrelation function) results indicated typical behavior reported by other authors, using different potentials in their DM simulations for iodine and silver ions.

Diffusion and thermo-driven migration of silver, palladium, and ruthenium nanoparticles in cubic SiC matrix using molecular dynamics

The diffusion and thermo-driven migration behaviors of metal fission products in cubic SiC are critical for determining the safety of a high-temperature gas-cooled reactor, and the molecular dynamics (MD) approach can describe the phenomenon from a microscopic perspective. The interactions of three metal elements, Ag, Pd, Ru, and SiC, were described using the Analytical Bond-Order Potential (ABOP). The diffusion coefficient of metal nanoparticles within the SiC matrix was calculated at various temperatures, and the results revealed that Ag > Pd > Ru. Furthermore, thermo-driven migration simulations were carried out using three alternative matrix morphologies: pure cubic SiC, nano-polycrystalline SiC, and SiC with a nanochannel. It is illustrated that Ag nanoparticles transport farthest in the SiC nanocrack from the high-temperature region to the low-temperature region and the magnitude is considerably greater than that in the other two cases. Therefore, the size of the SiC nanochannel and metal nanoparticles were investigated additionally, indicating that there are optimal-matching geometric parameters for Ag and Ru, but no noticeable effect on Pd nanoparticles. The findings of this study allow for the calculation of the diffusion coefficient used in source term analysis, as well as the examination of fission product migration behavior in a large temperature gradient field.

Studies of Ag Diffusion Processes into Thin-Film As2s3 Structures Doped With Sn under the Exposure of X-Ray Radiation

The processes of silver diffusion into thin-film structures (As2S3)0,995Sn0,005 under the X-ray radiation were studied. Thin-film layers of silver, about 12 nm thick, were deposited by vacuum thermal evaporation on the (As2S3)0,995Sn0,005 surface. The thin layer structures were irradiated with X-ray radiation in the range of absorbed doses of 0,3-0,6 Gy using the X-ray tube with a copper anode (voltage 45 kV, current 40 mA) as an X-ray source without any filters (the continuous spectrum of X-ray, or “white” spectrum). The possibility of X-ray images recording with their subsequent visualization using the chemical etching in a 5% solution of NaOH is shown.

Mechanistic calculation of the effective silver diffusion coefficient in polycrystalline silicon carbide: Application to silver release in AGR-1 TRISO particles

The silicon carbide (SiC) layer in tristructural isotropic (TRISO) fuel particles serves as a barrier to prevent the escape of fission products produced and not retained in the fuel kernel. The release of silver (Ag) is a concern due to the long half-life of the 110mAg isotope. However, accurately determining the fission gas release rate requires knowing the diffusion coefficient through the SiC layer. In this study, we leverage atomistic calculations of Ag diffusivity in SiC bulk and grain boundaries (GBs) to develop a mesoscale effective Ag diffusion coefficient (Deff) in SiC. Since GBs serve as pathways for Ag diffusion, Deff is defined as a function of temperature and microstructure variables. In particular, the size of SiC grains in the direction perpendicular to diffusion is shown to significantly affect Ag diffusion. The prediction of the mechanistic, mesoscale approach falls within one order of magnitude of empirical values. The temperature and microstructure-dependent effective Ag diffusivity in SiC is implemented in the fuel performance code Bison with a correction factor to predict Ag release from AGR-1 TRISO fuel particles. We hereby quantify the impact of SiC grain size on Ag release and improve Bison’s predictions.