Deposited Silver Films Research Articles

Research of electrode materials for the creation of multifunctional current sources with increased capacity as a components of the energy sector of an efficient urban environment

As part of creating a comfortable and safe environment, constructing energy-efficient residential and industrial buildings and structures that meet modern requirements and standards, the development of the production of environmentally friendly renewable and new individual energy sources is becoming especially relevant. In this regard, there is a need to increase the energy capacity of electrochemical cells. Research has been carried out on the metallized conductive materials creation based on rolled carbon non-woven material “Busofit” with the sequential application of metal coatings of titanium and silver using ion-plasma sputtering and electric pulse dispersion methods. It has been shown that surface layer metallization of the electrode material with titanium can improve the electrochemical cell characteristics. Additional silver film deposition leads to further cell performance improvement. It has been confirmed that the multilayer structure interfacial resistance between the carbon and the current collector has a significant effect on the conductivity of the electrochemical cell and the stability of its operation. The contact area increase of the electrode with the electrolyte leads to an increase in the rate processes occurring on the electrode surface and in the near-electrode space, which opens up prospects for increasing the energy intensity of the electrochemical system. A significant capacity increase of a water-based capacitor structure is achieved by the formation of a nanostructured dielectric layer of potassium titanate in the interelectrode space. It has been confirmed that the cell voltage cycling helps to stabilize the processes occurring in the surface layer of the electrode material at the interface and determining the range of mechanisms for transmitting electrical energy, which makes it possible to achieve higher energy intensity of the samples. Improvement of technological solutions in the field of ion-plasma technologies and the use of new perspective nanostructured materials creates the prerequisites for the creation of advanced automation and energy supply systems with a higher resource, which expands the possibilities of their use in various construction projects.

Ultra-thin silver films grown by sputtering with a soft ion beam-treated intermediate layer

Silver thin films have wide-ranging applications in optical coatings and optoelectronic devices. However, their poor wettability to substrates such as glass often leads to an island growth mode, known as the Volmer–Weber mode. This study demonstrates a method that utilizes a low-energy ion beam (IB) treatment in conjunction with magnetron sputtering to fabricate continuous silver films as thin as 6 nm. A single-beam ion source generates low-energy soft ions to establish a nominal 1 nm seed silver layer, which significantly enhances the wettability of the subsequently deposited silver films, resulting in a continuous film of approximately 6 nm with a resistivity as low as 11.4 µΩ.cm. The transmittance spectra of these films were found to be comparable to simulated results, and the standard 100-grid tape test showed a marked improvement in adhesion to glass compared to silver films sputter-deposited without the IB treatment. High-resolution scanning electron microscopy images of the early growth stage indicate that the IB treatment promotes nucleation, while films without the IB treatment tend to form isolated islands. X-ray diffraction patterns indicate that the (111) crystallization is suppressed by the soft IB treatment, while growth of large crystals with (200) orientation is strengthened. This method is a promising approach for the fabrication of silver thin films with improved properties for use in optical coatings and optoelectronics.

Wrinkle-bioinspired silver nanowire surface enhanced Raman scattering sensors for pesticide molecule detection.

We demonstrate wrinkle-bioinspired flexible SERS sensor covered by silver nanowire (AgNWs) network for the detection of pesticide molecules. Compared with the silver film deposition substrates, the wrinkle-bioinspired AgNWs SERS substrates show stronger SERS effect, which were attributed to the electromagnetic field enhancement posed by the relatively high density "hot spots" of AgNWs. In order to investigate the adsorption performance of wrinkle-bioinspired flexible sensors, we measured the corresponding contact angles of AgNWs on the substrate surfaces before and after plasma treatment and found that the AgNWs treated with plasma are more hydrophilic than that without plasma treatment. Additionally, the wrinkle-bioinspired SERS sensors show different SERS activities under different tensile strain, and the 10-6 mol/L concentration of Rhodamine dye (R6G) molecules can be detected by portable Raman spectra, reducing greatly detection cost. The surface plasmon resonance of AgNWs is induced by adjusting the deformation of AgNWs substrate, enhancing the SERS signal. This reliability of wrinkle-bioinspired SERS sensors is further verified by in situ detection of pesticide molecules.

High-performance flexible strain sensors based on silver film wrinkles modulated by liquid PDMS substrates.

Flexible strain sensors based on controllable surface microstructures in film-substrate systems can be extensively applied in high-tech fields such as human-machine interfaces, electronic skins, and soft robots. However, the rigid functional films are susceptible to structural destruction and interfacial failure under large strains or high loading speeds, limiting the stability and durability of the sensors. Here we report on a facile technique to prepare high-performance flexible strain sensors based on controllable wrinkles by depositing silver films on liquid polydimethylsiloxane (PDMS) substrates. The silver atoms can penetrate into the surface of liquid PDMS to form an interlocking layer during deposition, enhancing the interfacial adhesion greatly. After deposition, the liquid PDMS is spontaneously solidified to stabilize the film microstructures. The surface patterns are well modulated by changing film thickness, prepolymer-to-crosslinker ratio of liquid PDMS, and strain value. The flexible strain sensors based on the silver film/liquid PDMS system show high sensitivity (above 4000), wide sensing range (∼80%), quick response speed (∼80 ms), and good stability (above 6000 cycles), and have a broad application prospect in the fields of health monitoring and motion tracking.

Effect of a Deposited Silver Film on the Deformation Strength Properties of Track Membranes

Effect of a Deposited Silver Film on the Deformation Strength Properties of Track Membranes

Lithium-Silver Alloys: Solid-Solution Ranges for High Capacity Foil Electrodes

Silver is a promising electrode material for advanced lithium-based batteries, however it remains relatively unexplored due in part to the complexity of the lithium-silver phase diagram. [1] The larger opportunity is to realize the high capacity of lithium-rich phases with limited volume changes in a lithium-silver foil electrode.[2] ,[3] In order to accomplish this we must first understand the correlation between the equilibrium diagram and dynamic electrochemical phase formation.The lithium-silver equilibrium phase diagram consists of many solid solutions of varying lithium content and capacity. Notable phases (and their approximate compositions and gravimetric capacities based on total mass) are α (Li0-0.5Ag), β (Li1Ag, 230 mAh/g), γ3 (Li2Ag, 450 mAh/g), γ2 (Li4Ag, 800 mAh/g), γ1 (Li9Ag, 1500 mAh/g), and δ (Li50Ag, 3000 mAh/g). Early electrochemical studies of lithium-silver focused on sputter deposited silver films.[4] ,[5] These studies demonstrated the formation of three lithium-silver phases (β, γ3, and γ2) and exhibited poor capacity retention. The effect of deposition conditions (e.g. oxygen incorporation, rapid quenching) on the silver film and its electrochemical behaviour were unclear. More recently, lithium-rich (Li20Ag) composite foils were created by incorporating silver powder in molten lithium and then cooling. The resulting foils were then reversibly cycled between Li20Ag and Li5Ag (reversible capacity of 1600 mAh/g).2 Li20Ag has not been identified as an equilibrium phase but was also not identified as a composite of multiple Li-Ag phases. Each phase identified in the equilibrium diagram exhibited a wide, temperature-dependent composition range. The field needs conclusive identification of lithium-silver phases (including solid solution ranges) as a function of electrochemical conditions for reversible high capacity lithium-silver foil electrodes to be realized.Here we report on the electrochemical lithiation of silver foil using a suite of in-situ and operando methods over a wide range of temperatures and current densities. Two types of pure silver foil (99.99%, ESPI, 25 μm thick; and 99.9%, Shizendo, 2 μm thick) were galvanostatically cycled against lithium metal using Conflat cells[6] and standard electrolytes. Thick foils were used as a pure reference to understand the effects of diffusion; thin foils enabled higher rates and more meaningful x-ray diffraction studies.Potential vs. composition data is provided in Fig. 1a). Results from thick foils are very complicated. In most cases the highest composition observed was approximately Li3Ag. This does not align with a phase boundary in the established equilibrium phase diagram. A solid solution is likely present at intermediate temperatures as a plateau at approximately 10 mV vs. Li/Li+ is apparent. Ex-situ x-ray diffraction of thick lithiated foils (not shown) indicated β and γ3 Li-Ag phases were present on the lithium-facing surface of the electrode. However, the backside of the electrode was nearly pristine Ag. Such discrepancies can be attributed to slow diffusion, low foil porosity, and the penetration depth of our 8 keV X-rays (a few μm).Thin silver films exhibited more complex electrochemical behaviour at high temperatures compared to previous reports of sputter deposited thin films.4,5 A plateau at approximately 150 mV vs. Li/Li+ can be attributed to the growth of the β phase of Li-Ag. A second plateau at approximately 60 mV vs. Li/Li+ corresponds with the expected formation of γ3 Li-Ag. Two additional features loosely correlate with the expected composition of γ2 and γ1Li-Ag. However, only γ2 is expected as γ1 is only thought to be stable to 120°C. Operando X-ray diffraction patterns collected from a thin silver foil lithiated at 110°C are provided in Fig. 1b). β, γ3, and γ2 Li-Ag phases, and broad solid solution ranges, are present. There is no clear structural or electrochemical evidence of the formation of γ1 Li-Ag. Given that γ1 has an approximate composition of Li10Ag and the high capacity of lithium-silver foil electrodes depend on even more lithium rich compositions (e.g. Li20Ag) extensive studies on the formation range of all Li-Ag phases are required. Electrochemically-accessible phase diagrams, including solid-solution ranges, based on ex-, in-situ, and operando electrochemical and structural measurements will be provided.[1] Okamoto, J. Ph. Eq., 38, 70 (2017).[2] Jin et al, J. Am. Chem. Soc., 142, 8818 (2020).[3] Wu et al., Adv. Energy Mater., 11, 2003082 (2021).[4] Taillades and Sarradin, J. Power Sources, 125, 199 (2004).[5] Xie et al., J. Solid State Electrochem., 15, 2031 (2011).[6] Fleischauer et al., J. Electrochem. Soc., 168, A398 (2019). Figure 1. a) Potential vs. composition curves for the insertion of lithium into silver foils. Electrochemical conditions are indicated. b) Operando electrochemical and x-ray diffraction patterns of the lithiation of silver foil. Figure 1

Tollens Reaction‐Based Integration of Thin Film Wall Electrodes into Microfluidic PDMS Devices

AbstractThe integration of electrodes into microfluidic devices is a prerequisite for several key technologies such as electrophoresis, dielectrophoresis, electrowetting, or analysis and manipulation of biological cells in organ‐on‐a‐chip applications. However, conventional sputtering or metal deposition methods result in electrodes on the top or the bottom of the microfluidic device leading to either an inhomogeneous electrical field or considerable restrictions regarding optical analysis methods. Here, a novel method for integrating electrodes into microfluidic devices based on the deposition of silver films on the sidewalls of microfluidic channels by Tollens reaction is presented. Aldehydes diffuse readily through polydimethylsiloxane walls and reduce noble metal ions such as silver, which in turn precipitate and deposit on the phase border as homogeneous thin layers. The process results in sidewall electrodes that adopt the channel's geometry and offer a highly homogeneous electrical field in the case of a rectangular channel. The electrodes were analyzed by dissipative X‐ray (EDX) and electrical impedance spectroscopy, while the electrical field was visualized by particle image velocimetry. The method can fabricate electrodes in different shapes rendering the process highly promising for a wide range of different electrochemical applications in the field of microfluidics, while simultaneously enable optical analysis methods.

ELECTRODEPOSITION OF SILVER THIN FILMS ON A GOLD SUBSTRATE IN THE PRESENCE OF OCIMUM GRATISSIMUM (Og) AND VERNONIA AMYGDALINA (Va) PLANT LEAF EXTRACTS.

Electrodeposition an advanced thin film deposition method originally used for decorative purposes and now widely used in industrial applications such as electronics, phonics, magnetic recording and protective coatings, has also been used for the production of size and structure-controlled nanoparticles. In this research, the electrodeposition of silver (Ag) films on gold (Au) substrates with two plant (Ocimum gratissimum (Og) and Vernonia amygdalina (Va) leaf extracts as additives was explored . The effect of these leaf extracts immediately after addition and after a prolonged exposure in the electrolyte on the silver deposits was studied using cyclic voltammetry (CV), chronoamperometry (CA) and linear sweep voltammetry (LSV). Silver thin films were electrodeposited on gold film from an electrolyte of 5 mM AgNO3 and later 5 mM AgNO3 +0.1 M KNO3 for 10 minutes, using a double potential step protocol and potentials -0.15 V and -0.3 V with and without the plant leaf extracts. As silver was grown on the gold substrate, silver nanoparticles were also discovered to have been formed in the electrolyte. Though the deposition potential in the presence of the plant leaf extracts affected the kinetics of the silver deposition on the gold substrate, it only slightly affected the silver film thickness on the gold. CV graphs with the plant leaf extracts show lower current densities indicating a slowing down of the deposition/dissolution rates of silver probably due to the adsorption of the leaf extracts on the surface of the growing silver films which may have affected the transport of silver ions (Ag+) towards the electrode and impacted on the silver deposition/dissolution kinetics. The deposited silver film thickness was 7 nm to 8 nm with the Og leaf extract and 1.5 nm to 2 nm with the Va leaf extract. Atomic Force microscope (AFM) was used for viewing the silver films and the mean grain sizes of the Og silver films was calculated to be . This was larger than those of the Va silver films calculated to be While the Va silver films surface roughness was higher at 10.6 , that of the Og silver film was 9.3.

Nonconventional driving force for selective oxidative C\u2013C coupling reaction due to concurrent and curious formation of Ag0

Is it possible to ‘explore’ metal’s intrinsic property—a cohesive interaction—which naturally transform M0 into an aggregate or a particle or film for driving oxidative C–C bond formation? With this intention, reduction of [Ag(NH3)2]+ to Ag0 with concurrent oxidation of different phenols/naphthols to biphenyls was undertaken. The work is originated during careful observation of an undergraduate experiment—Tollens’ test—where silver mirror film deposition takes place on the walls of borosilicate glass test tube. When the same reaction was carried out in polypropylene (plastic-Eppendorf) tube, we observed aggregation of Ag0 leading to floating Ag-particles but not silver film deposition. This prompted us to carry out challenging cross-coupling reaction by ONLY changing the surface of the reaction flask from glass to plastic to silicones. To our surprise, we observed good selective oxidative homo-coupling on Teflon surface while cross-coupling in Eppendorf vial. Thus, we propose that the formation of biphenyl is driven by the macroscopic growth of Ag0 into [Ag-particle] orchestrated by Ag…Ag cohesive interaction. To validate results, experiments were also performed on gram scale. More importantly, oxidation of β-naphthol carried out in quartz (chiral) tube which yielded slight enantioselective excess of BINOL. Details are discussed.

Electromagnetic Interference Shield of Highly Thermal-Conducting, Light-Weight, and Flexible Electrospun Nylon 66 Nanofiber-Silver Multi-Layer Film.

A light-weight, flexible electromagnetic interference (EMI) shield was prepared by creating a layer-structured metal-polymer composite film consisting of electrospun nylon 66 nanofibers with silver films. The EMI shielding effectiveness (SE), specific SE, and absolute SE of the composite were as high as 60.6 dB, 67.9 dB cm3/g, and 6792 dB cm2/g in the X- and Ku-bands, respectively. Numerical and analytical calculations suggest that the energy of EM waves is predominantly absorbed by inter-layer multiple reflections. Because the absorbed EM energy is dissipated as heat, the thermal conductivity of absorption-dominant EMI shields is highly significant. Measured thermal conductivity of the composite was found to be 4.17 Wm−1K−1 at room temperature, which is higher than that of bulk nylon 66 by a factor of 16.7. The morphology and crystallinity of the composite were examined using scanning electron microscopy and differential scanning calorimetry, respectively. The enhancement of thermal conductivity was attributed to an increase in crystallinity of the nanofibers, which occurred during the electrospinning and subsequent hot pressing, and to the high thermal conductivity of the deposited silver films. The contribution of each fabrication process to the increase in thermal conductivity was investigated by measuring the thermal conductivity values after each fabrication process.

Application of a low-cost silver/PET catalyst for hydrogen peroxide reduction reaction

This work focuses on chemical preparation of structured silver film onto polyethylene terephthalate (PET) substrate and improvement in electroreduction activity of the as-prepared Ag/PET electrode material as cathode catalyst for hydrogen peroxide (H2O2) reduction reaction (HPRR). The deposited silver film is homogeneous and has an open microporous structure, resulting in a high activity of the Ag/PET electrode for the HPRR. We show that the Ag/PET electrode can efficiently catalyze the HPRR with an onset potential of 0.1 V (vs.SCE).

Plasmon resonance in CVD graphene-silver nanoparticle composites

Investigation results on the morphology and optical properties of polymer-graphene composites with silver nanoparticles deposited by pulsed laser ablation are presented. Graphene was obtained by the CVD method and transferred to PET/EVA polymer through thermal pressing. It has been established that with an increase in the thickness of deposited silver film, a transition from bimodal distribution of particles to formation of elongated rectangular nanostructures is observed. A similar phenomenon can be explained by accumulation of deposited silver particles along the boundaries of adjacent graphene crystallites. It is experimentally shown that the degree of plasmon absorption depends strongly on the mass-average thickness of the deposited metal coating and size of nanoparticles. Deepening of the peak of plasmon absorption simultaneously with a general decrease in sample transparency occurs when the film thickness is changed up to 6 nm. A further increase in thickness does not affect the intensity of plasmon absorption and scattering, but leads to a general decrease in transparency of the polymer-graphene-silver composite. It is shown that the highest degree of radiation attenuation is in the wavelength range from 400 to 600 nm.

Low-temperature reducible particle-free screen-printable silver ink for the fabrication of high conductive electrodes

In this contribution, screen printing of aqueous based particle-free silver ink is addressed using combustion chemistry, where inks embody a redox mixture of silver nitrate and citric acid in the presence of a binder, sodium-carboxymethylcellulose. The exothermic reaction at ~ 176 °C results in the formation of pure silver. Screen-printing process is optimized for three different silver loadings (14%, 18% and 22%) in ink. In depth rheological study of the inks reveals thixotropic nature and the ink with 18% of silver possessing a viscosity of 328 Pa .s has a recovery rate of 84% at 110 s with a shear rate of 1 s−1. The deposited silver films (~ 3 µm thick) on both rigid-glass and flexible-polyamide substrates have shown an electrical conductivity of 4.2 × 106 S m−1 and 2.6 × 106 S m−1 respectively. Film adhesion on glass substrates categorized under 3B as per ASTM D-3359. Present screen-printed silver films find their application as a gate electrode in thin film transistors (TFTs). The TFTs comprising of indium zinc tin oxide–semiconductor and sodium β -alumina dielectric with screen-printed silver as a gate electrode exhibited the saturation mobility, on:off ratio and threshold voltage of 0.88 cm2 V−1 s−1, 102 and ~ 0.3 V respectively.

A new approach for deposition of silver film from AgCl through successive ionic layer adsorption and reaction technique

An attempt was made to deposit thin film of silver onto the glass substrate by using AgCl precursor, instead of conventional precursor AgNO3 with vitamin C by inexpensive and convenient successive ionic layer adsorption and reaction (SILAR) method. The deposited silver thin film was characterized by X-ray diffraction (XRD) analysis, scanning electron microscope (SEM), UV-visible and electrical I-V study. The diffraction study showed FCC structure of metallic silver in good agreement with the standard values of JCPDS (04–0783). SEM reveals flower like nano particles produced on the substrate. The surface plasmon resonance (SPR) peak in the UV-visible spectrum shows maximum absorption at 350 nm. The film shows an ohmic behavior and its electrical resistivity was found ~103 Ω·cm at room temperature.

Interference enhancement in SERS spectra of rhodamine 6G: Relation to reflectance

We analyze how the presence of an optical Fabry-Pérot cavity affects the surface enhanced Raman (SERS) bands of rhodamine 6G (R6G) in terms of their intensity. The study is focused on the relation between the intensity of the SERS bands and the reflectance which is inherent to the examined structure rather than on the enhancement factor. For this purpose, multilayered Si/SiO2 structures decorated with discontinuous vapour deposited silver films were utilized as an active layer for SERS and a bond for the solution of R6G. We related the intensity of the SERS bands in R6G caused by interference to the reflectances at the wavelengths of the excitation and scattered light.

Dark plasmonic mode based perfect absorption and refractive index sensing.

Dark plasmonic resonances in metallic nanostructures are essential for many potential applications such as refractive index sensing, single molecule detection, nanolasers etc. However, it is difficult to excite the dark modes in optical experiments and thus the practical applications are severely limited. Herein, we demonstrate a simple method to experimentally excite the quadrupolar and higher-order plasmonic modes with normal incident light. By directionally depositing silver films onto the sidewalls of metal-covered one-dimensional grating, we have experimentally observed a series of asymmetrical resonances at the plasmonic ranges of silver gratings. Interestingly, both of the reflection and transmission coefficients of high-order plasmonic modes are reduced to around zero, demonstrating the perfect absorption very well. The corresponding numerical simulations show that these resonances are the well-known dark modes. Different from the conventional dark modes in plasmonic dimers, here the dark modes are the electric oscillations (as standing waves) within the silver sidewalls that are excited by charge accumulation via the bright plasmonic resonance of the top silver strips. In addition to the simple realization of perfect absorption, the dark modes are found to be quite sensitive to the environmental changes. The experimentally measured reflective index sensitivity is around 458 nm per RIU (refractive index unit), which is much higher than the sensitivity of the metal-covered grating without silver sidewalls. This research shall pave new routes to practical applications of dark surface plasmons.

Deposition of silver films on copper nanopowders by three-times electroless plating

In order to enhance the oxidation resistance of a copper substrate, silver films were deposited by electroless plating onto pure copper nanopowder. However, the efficiency of electroless plating for nanopowders is very low. Silver-coated copper nanopowders can be successfully achieved by three-times electroless silver plating on copper nanopowder. The microstructure and the chemical composition of the silver-coated copper nanopowders were systematically analyzed. The silver films have shown excellent oxidation resistance, according to the results of accelerated temperature cycling tests. The silver-coated copper nanopowders were characterized using scanning electron microscopy and X-ray diffraction. Following conclusions were obtained under the optimum condition that the reaction temperature was 50 °C, the dosage of EDTA was 4 g/L, hypophosphite (NaH2PO2) was 20.6 g/L. When the silver content reached 25 %, silver was homogeneously distributed around copper nanopowders.

Metal nano-particles sizing by thermal annealing for the enhancement of surface plasmon effects in thin-film solar cells application

The optical properties and surface plasmon effects of different thickness of silver film grown on a silicon substrate were experimentally and numerically investigated. By modifying the film thickness and the annealing temperature, the size of metal nanoparticles (MNPs) can be manipulated. The reflectance of silver film deposited onto silicon wafers were adjusted by controlling the film thickness and annealing temperature. The experimental results show the MNPs grew larger with thinner deposition of silver film, and this has a correlation to the reflectance. We found that the thermal annealing temperature affects the optical properties of the MNPs, and this enhances the E-field intensity on the MNPs, and contributes to the improvement in the conversion efficiency of solar cells. This paper describes our attempts to develop a simple method that can replace the previously reported processes of lithography and thermal vacuum evaporation of the silver film and MNPs preparation.

Ag films grown by remote plasma enhanced atomic layer deposition on different substrates

Silver (Ag) layers were deposited by remote plasma enhanced atomic layer deposition (PALD) using Ag(fod)(PEt3) (fod = 2,2-dimethyl-6,6,7,7,8,8,8-heptafluorooctane-3,5-dionato) as precursor and hydrogen plasma on silicon substrate covered with thin films of SiO2, TiN, Ti/TiN, Co, Ni, and W at different deposition temperatures from 70 to 200 °C. The deposited silver films were analyzed by x-ray photoelectron spectroscopy (XPS), atomic force microscopy (AFM), scanning electron microscopy (SEM), transmission electron microscopy (TEM) with energy dispersive x-ray spectroscopy, four point probe measurement, ellipsometric measurement, x-ray fluorescence (XRF), and x-ray diffraction (XRD). XPS revealed pure Ag with carbon and oxygen contamination close to the detection limit after 30 s argon sputtering for depositions made at 120 and 200 °C substrate temperatures. However, an oxygen contamination was detected in the Ag film deposited at 70 °C after 12 s argon sputtering. A resistivity of 5.7 × 10−6 Ω cm was obtained for approximately 97 nm Ag film on SiO2/Si substrate. The thickness was determined from the SEM cross section on the SiO2/Si substrate and also compared with XRF measurements. Polycrystalline cubic Ag reflections were identified from XRD for PALD Ag films deposited at 120 and 200 °C. Compared to W surface, where poor adhesion of the films was found, Co, Ni, TiN, Ti/TiN and SiO2 surfaces had better adhesion for silver films as revealed by SEM, TEM, and AFM images.

Synergistic and Antagonistic Ligand Effects in the Transformation of Silver Compounds of Keto‐ and Cyano‐Functionalised Oximates and Nitronates: A Systematic Study Using Thermal Analysis

Molecular silver compounds are target precursor molecules for the deposition of silver films from solution. The thermal decomposition of silver complexes of nitro and nitroso derivatives of malononitrile, cyanoacetamide and methyl cyanoacetate as well as with nitroacetamide and methyl nitroacetate was investigated for the first time in a systematic manner. The analysis of the evolving gases by means of infrared spectroscopy or mass spectrometry revealed that intramolecular redox reactions had a significant impact on the reaction mechanism, in particular the interactions of the nitro and nitroso functionalities with amido and ester groups. The studied ligands bearing cyano groups typically lead to the intermediary formation of silver cyanide, whereby metallic silver is formed only at higher temperatures. Silver complexes of nitroacetamide and methyl nitroacetate, however, undergo decomposition to metallic silver at temperatures already below 200 °C. Thin films of silver on glass substrates could be synthesised by spincoating of these precursors and subsequent annealing. Higher conversion temperatures lead to more uniform surface coverage and lower film roughness.