Bath Components Research Articles

General framework for quantifying dissipation pathways in open quantum systems. I. Theoretical formulation.

We present a general and practical theoretical framework to investigate how energy is dissipated in open quantum system dynamics. This is performed by quantifying the contributions of individual bath components to the overall dissipation of the system. The framework is based on the Nakajima-Zwanzig projection operator technique, which allows us to express the rate of energy dissipation into a specific bath degree of freedom by using traces of operator products. The approach captures system-bath interactions to all orders, but is based on second-order perturbation theory on the off-diagonal subsystem's couplings and a Markovian description of the bath. The usefulness of our theory is demonstrated by applying it to various models of open quantum systems involving harmonic oscillators or spin baths and connecting the outcomes to existing results such as our previously reported formula derived for locally coupled harmonic baths [Kim and Franco, J. Chem. Phys. 154, 084109 (2021)]. We also prove that the dissipation calculated by our theory rigorously satisfies thermodynamic principles such as energy conservation and detailed balance. Overall, the strategy can be used to develop the theory and simulation of dissipation pathways to interpret and engineer the dynamics of open quantum systems.

General framework for quantifying dissipation pathways in open quantum systems. II. Numerical validation and the role of non-Markovianity.

In the previous paper [C. W. Kim and I. Franco, J. Chem. Phys. 160, 214111-1-214111-13 (2024)], we developed a theory called MQME-D, which allows us to decompose the overall energy dissipation process in open quantum system dynamics into contributions by individual components of the bath when the subsystem dynamics is governed by a Markovian quantum master equation (MQME). Here, we contrast the predictions of MQME-D against the numerically exact results obtained by combining hierarchical equations of motion (HEOM) with a recently reported protocol for monitoring the statistics of the bath. Overall, MQME-D accurately captures the contributions of specific bath components to the overall dissipation while greatly reducing the computational cost compared to exact computations using HEOM. The computations show that MQME-D exhibits errors originating from its inherent Markov approximation. We demonstrate that its accuracy can be significantly increased by incorporating non-Markovianity by exploiting time scale separations (TSS) in different components of the bath. Our work demonstrates that MQME-D combined with TSS can be reliably used to understand how energy is dissipated in realistic open quantum system dynamics.

Predict the surface free energy of Ti/Zr/V chemical conversion coating on nickel by machine learning approach: Trees vs. neurons

The surface properties of chemical conversion treated materials have received increasing attention and surface free energy (SFE) is an important indicator of it. In this study, an environment-friendly Ti/Zr/V chemical conversion coating was deposited on the nickel and Artificial Neural Network (ANN), Random Forest (RF), and Extra Trees (ET) models were applied to further investigate the relationship between the SFE and the compositions of the conversion bath. The accuracy of SFE prediction of three machine learning models was quantified, and the obtained results reveal that the correlation coefficients for the ANN, RF, and ET models are 0.958, 0.979, and 0.963 for the prediction of dispersion components and 0.964, 0.942 and 0.921 for the prediction of polar components, respectively, and the ANN model shows more outstanding performance in general. The errors in the prediction of the ANN model for the polar and dispersion components of SFE are 0.336 and 0.421, respectively, which are smaller than the extended uncertainties obtained from conventional experimental methods. The obtained machine learning models can accurately predict the variations of SFE for modest changes in the conversion bath components, thus linking the formation mechanism of coating with the variations of SFE.

Exploring the potential of nickel-chloride bath for electroforming of pure nickel and nickel composites

Electroforming is becoming increasingly important as a reliable method for the production and replication of independent parts. Researchers are continually striving to reduce production costs for the fabrication of complex tools with the highest precision and lowest cost, and electroforming is a key technique for achieving this goal. The present research aimed to produce pure nickel foils via electroforming using a simple and inexpensive nickel-chloride bath, which has not been previously utilized for electroforming. The effects of saccharin concentration, nickel-chloride concentration, direct current density, and the use of graphite as an insoluble anode were investigated. The surface morphology of the electroformed products was characterized through scanning electron microscopy (SEM) and their chemical composition was analyzed using energy dispersive x-ray (EDX) and x-ray diffraction (XRD) pattern. The microhardness of the foils was determined using the Vickers hardness test. Results showed that specimens produced using the nickel-chloride bath had a good surface appearance with acceptable brightness and satisfactory microhardness. Ten electroforming tests were conducted to determine the optimal bath components, pH, and direct current density for the fabrication of pure nickel products. It was found that these parameters had a significant influence on the quality of the appearance and surface morphology of the foils. In addition, using a graphite anode was seen to reduce the cathode current efficiency as compared to a soluble nickel anode and was affected by the preferred orientation of nickel crystal plates. It can be concluded that the nickel-chloride bath has excellent potential for the production of pure nickel products using the electroforming method.

Utilization of Microencapsulated Thyme Essential Oil for Aroma Treatment of Wool Fabric

Background: With rising global trends and changing lifestyles in fashion, beauty as well as healthcare, the awareness of consumers has enforced the evolution of specialty value-added textiles. Essential oils and basic aromatherapy ingredients are microencapsulated and applied to the materials to provide a therapeutic effect and long-lasting aromas. The present study was carried out to prepare thyme essential oil microcapsules using a complex coacervation technique. The prepared microcapsules were applied on wool fabric using pad-dry-cure method by optimizing various variables of aroma treatment.
 Methods: Thyme essential oil was used based on its aromatic and therapeutic properties. A complex coacervation technique of microencapsulation was used to prepare thyme oil microcapsules. The padding bath components and treatment variables were optimized based on the presence of microcapsules on wool fabric as observed under a stereo zoom microscope, aroma durability to washing and improved properties of treated material regarding bending length, flexural rigidity and crease recovery angle. The aroma treatment was given on wool fabric using pad-dry-cure method.
 Results: Optimized variables for aroma treatment were 60 g/l microcapsule gel, two g/l softeners and ten g/l binder concentration, 1:20 material to liquor ratio, 35 ºC temperature, and 30 minutes treatment time as at these conditions more number of microcapsules, longer wash durability and better fabric properties in terms of bending length, flexural rigidity and crease recovery angle were observed. Aroma-treated wool fabric were dried at 70 ºC temperature for 4 minutes and cured at 100 ºC for 60 seconds.
 Conclusions: Thyme essential oil has many reported therapeutic properties therefore microencapsulated thyme basic oil-treated wool fabric can be used for apparel, home, and healthcare textiles. Higher concentrations of microcapsule gel and lower concentrations of softener and binder promoted the deposition of a maximum number of microcapsules on wool fabric. Complex coacervation techniques of microencapsulation for preparation of thyme essential oil microcapsules and pad-dry-cure method to impart durable aroma treatment on wool are needed to acquire long term sustained finish.

Structure Performance Correlation of N-Heterocyclic Oligomer Leveler for Acid Copper Plating of Advanced Interconnects

Levelers, as an essential part of organic additives in copper electroplating, play a crucial role in the fabrication of sophisticated interconnects in integrated circuits, packaging substrates, and printed circuit boards. In this work, four N-heterocyclic oligomers were synthesized and characterized, along with investigations of their electrochemical behaviors and their synergism with other bath components. The corresponding effects of the oligomers on the deposited copper films were analyzed by morphological and compositional characterizations. The leveling mechanism of the oligomers was further discussed with the aid of quantum chemical calculations. The results exhibit that each of these N-heterocyclic oligomers holds a particular degree of leveling ability. The oligomer of 1,3-bis(1-imidazolyl)propane and 1,3-dichloro-2-propanol (IPIEP) is the best leveler for THs plating compared with the other three oligomers. It was found that the hydroxyl group in IPIEP enhances the hydrophilicity of the modified molecule and triggers a more stable complexation between IPIEP and H2O-Cu(I)-MPS. Moreover, imidazole demonstrates a better practicality than piperazine. This work recommends the combination of N-heterocycles in planar conformation with modification by the hydroxyl group to synthesize high-performance straight-chain levelers.

Eco-friendly TEMPO/laccase/O2 biocatalytic system for degradation of Indigo Carmine: operative conditions and laccase inactivation.

The biocatalytic system laccase/TEMPO/O2 has attracted the attention of researchers over the past two decades. A variety of applications for the system include organic synthesis, modification of cellulose, and oxidative degradation of environmental contaminants. A rigorous and predictable quantitative assessment of the change in enzymatic activity under the influence of a mediator is important for such a system. In this study, the operative conditions for carrying out a model reaction for the degradation of the synthetic dye Indigo Carmine in the presence of Trametes versicolor laccase/TEMPO were determined and the enzyme inactivation under the action of a mediator and substrate was studied. The long-term stability of Trametes versicolor laccase was assessed and the regression model of the response surface of laccase activity under the influence of TEMPO was created. It has been shown that laccase is inactivated in the presence of TEMPO, but the addition of the dye, CuSO4 or CuCl2 reduces this effect. The system under study can be used repeatedly for the Indigo Carmine decolorization, however, a gradual falling rate during the process is observed from cycle to cycle. This is due to two reasons - firstly, a decrease in the enzyme activity with each batch and secondly, the consumption of the mediator (22% within 5 days). Relatively high enzyme activity (>40%) is maintained after 73 cycles (1 portion of IC contained 25 μM) using 500 μM TEMPO and 0.12 U mL-1 laccase. The laccase/TEMPO system has shown its effectiveness in the treatment of artificial wastewater containing high concentrations of Indigo carmine (0.5 g L-1). In this case, the dye solution becomes 100% colorless within 5 hours in the presence of dye bath components and within 7.5 hours in a buffer solution.

Aliphatic oxime 3-(hydroxyimino)pentan-2,4-dione as new potential mediator for laccase-catalyzed decolorization of dyes

Aliphatic oxime HIPD (3-(hydroxyimino)pentan-2,4-dione) was studied as mediator of laccase (from Trametes versicolor) catalyzed decolorization and detoxication of eight structurally diverse synthetic dyes with typical chromophores including the azo dyes (Acid Red 1, Methyl Orange and Mordant Blue 13), indigo dye (Indigo Carmine), triphenylmethane dyes (Methyl Green, Crystal Violet), anthraquinone dye (Reactive Blue 4) and thiazine dye (Methylene Blue). The results demonstrated the potential and limitations of using 3-(hydroxyimino)pentane-2,4-dione as mediator for enzymatic decolorization of various type dyes. In the presence of a laccase-mediator system almost 100 % biodegradation was observed for Indigo Carmine, Acid Red 1, Methyl Orange and Reactive Blue 4 within 3 h. At the same time, the proposed laccase-mediator system does not decolorize Methylene Blue and exhibits lower efficiency in the degradation of triphenylmethane dyes in comparison with azo dyes. The studied system can be used repeatedly for wastewater treatment. Phytotoxicity tests of the solutions before and after treatment with laccase-mediator system indicated that dyes are converted into low-toxicity metabolites. The proposed system has demonstrated its efficiency in the treatment of artificial wastewater containing high concentrations of azo dyes (0.5 g L−1) and other auxiliaries used in the textile industry. Color reductions of 92 % and 83 % were achieved using laccase-mediator system for Acid Red 1 and Methyl Orange for 7 days in the presence of dye bath components.

Brass Alloy Coatings Electrodeposited from an Environmentally Friendly Alkaline Lactate Bath under Different Operating Conditions

The electroplating of brass alloy coatings onto a steel substrate was established using a lactic acid solution under diverse practical conditions. CuSO4.5H2O, ZnSO4.7H2O, CH3CHOHCOOH, and anhydrous Na2SO4 were used to make the deposition bath. The impact of bath components, deposition current, as well as temperature on the current efficiency (CE) and alloy microstructure was examined. The deposition of the alloy is of the normal type. The CE is good, and it improves when the [Zn2+] / [Cu2+] ratio in the bath increases. On the other hand, the efficacy declines when the current density, temperature, and lactic acid concentration increase. By elevating the applied current density, or raising the concentration of the Zn2+ ions in the tub, the amount of Zn metal in the plated alloy is increased. SEM, energy dispersion X-ray, and X-ray diffraction techniques are being used to investigate the coating’s morphology and crystal texture. The presence of copper and zinc metals in the deposit was confirmed by EDX analysis. The new bath’s deposits are well-crystalline and contain a Cu5 Zn8 phase. The bath’s throwing power and throwing index are determined, and it is found that the alkaline lactate tub has satisfactory throwing power and throwing index.

Comprehensive Characterization of All Inorganic and Organic Components in Neutral Tin Plating Bath for Electronics Applications

Abstract Tin plating at neutral and near-neutral pH is the preferable process in the application of electronic components such as capacitors and resistors, where the chemically sensitive ceramic and glass portions can be damaged by highly acidic solutions (often used in semiconductor packaging processes). Stannous ions are not as stable at elevated pH due to oxidation and hydrolysis, and plating demands the use of a large number of additives making the process control very challenging. Various analytical techniques are developed for automatic and comprehensive characterization of all inorganic and organic bath components including simultaneous detection of conductive salt, anti-whisker and chelator by near-infrared (NIR) spectroscopy, brightener by potentiometric titration, stannous ions by electrochemical method, and the breakdown stannic ions by spectro-titration.

Theory of dissipation pathways in open quantum systems.

We introduce a simple and effective method to decompose the energy dissipation in the dynamics of open quantum systems into contributions due to individual bath components. The method is based on a vibronic extension of the Förster resonance energy transfer theory that enables quantifying the energy dissipated by specific bath degrees of freedom. Its accuracy is determined by benchmarking against mixed quantum-classical simulations that reveal that the method provides a semi-quantitative frequency-dependent decomposition of the overall dissipation. The utility of the method is illustrated by using a model donor-acceptor pair interacting to a thermal harmonic bath with different coupling strengths. The method can be used to identify the key features of a bath that leads to energy dissipation as required to develop a deep understanding of the dynamics of open quantum systems and to engineer environments with desired dissipative features.

Thin film to nano copper deposition by special additives on an ecofriendly electroless bath

In this work we report the study of some special additives on ecofriendly electroless baths with pentahydroxylic substance xylitol as a chelating agent and glyoxylic acid as the reductant. Three additives, methanesulphonic acid, thioglycolic acid, and vitamin C were added to this bath. All the electroless baths are stable at alkaline medium above pH 12.0, at the temperature of 45 °C. Potassium hydroxide is used as pH controller and all the three additives exhibited best results at different pH values. Methanesulphonic acid helps the bath components to complex with copper metal and is biodegradable. Thioglycolic acid is used for bath stability and also as an inhibitor in copper deposits. Vitamin C added produces uniformity and high-quality coatings. The deposition rate decreased one by one among the additives, but end up with a compact, bright, and pure copper deposits. The surface morphology, shape and roughness values of those additives are proved by the scanning and power microscopy. All structural properties were analyzed by the diffraction method.

Optimization of High-Speed Electrolytic Plating of Copper Pillar to Achieve a Flat Top Morphology and Height Uniformity

Abstract Cu plating bath for high-speed electrodeposition of Cu pillar was designed in consideration of a flat top morphology of pillar and a pillar height uniformity. An ideal polarization curve was assumed for the flat top morphology. To obtain the ideal polarization curve, an effect of organic additive concentration and solution agitation on the polarization curve were investigated. The basic bath components were optimized considering a Wagner number to improve the pillar height uniformity. To confirm the pillar top morphology and the pillar height uniformity, a 300-mm diameter wafer was plated with Cu at 20 A/dm2. As a result, improved pillar top morphology and pillar height uniformity were obtained. The optimized plating bath was applied to the plating of a large-size panel of 415 × 510 mm.

Nanoscale Ni-Mo-Pt Alloy Catalyst with Tuneable Composition for Hydrogen Economy: Electrosynthesis and Characterisation

In the search for alternative and renewable energies that will finally allow abandoning the use of fossil fuels once and for all, hydrogen energy is among the most promising solutions able to fuel any kind of device independent of its size. The energy cycle of hydrogen needs a large infrastructure of highly efficient catalysts used in both electrolysers, which produce hydrogen gas, as well as fuel cells, where the energy stored in the hydrogen bond is converted into electrical current.The conversion of hydrogen works most effectively in acidic media, where the most effective and chemically stable material is platinum. The low abundancy and associated high cost of Pt make it impossible to provide a large-scale infrastructure using the commercial Pt/C catalyst. Alternatives must be found to substantially reduce the amount of Pt used as catalyst material without compromising its sustainability.A facile electrodeposition process from aqueous media allows the one-step synthesis of a Ni-Mo-Pt alloy for use in both hydrogen evolution reaction (HER) and energy conversion systems such as fuel cells. In a previous study, mesoporous Ni-Pt films were synthesised by electrodeposition and thoroughly characterised towards HER, finding that the reaction in 0.5 M H2SO4 was efficient, stable and reproducible. However, some leaching of Ni into the sulfuric acid was observed under open circuit conditions [1,2]. In this study, molybdenum is introduced into the previously investigated Ni-Pt alloy to increase the stability of the material in acidic media. With respect to the electrolyte used for the synthesis of the Ni-Pt alloy, all bath components were kept the same except for the addition of sodium molybdate and citric acid. The latter complexes Mo(VI), thus enabling its co-deposition.Due to a pH-dependent complexation of Mo(VI) by citric acid, the composition of the Ni-Mo-Pt alloy is strongly pH-dependent and can further be fine-tuned to the needs of the specific application by changing the electrodeposition parameters. The Mo contents obtained reach from 10 at% up to 50 at%. Alloys with the highest Mo content, however, trigger phase separation.Using potentiostatic electrodeposition, continuous thin films of Ni-Mo-Pt are obtained on a Cu-coated Si substrate. However, the growth of globular particles is favoured on a hydrophobic substrate, such as a carbon-based gas diffusion layer (GDL) typically found in a fuel cell set-up. Further, using pulse electrodeposition, nanoparticles with a mean diameter down to 10 nm are successfully obtained.For HER in 0.5 M H2SO4, Ni rich alloys with low Pt contents (between 1 at% and 5 at%) are investigated, while alloys with higher Pt contents can provide sufficient electrochemical stability for oxygen reduction reaction (ORR) in a proton exchange membrane (PEM) fuel cell. The stability of alloys with varying composition is determined by incubation in 0.5 M H2SO4. Cyclic voltammetry curves in the same media are performed on Ni-Mo-Pt nanoparticles in order to activate the surface and remove any contaminants as a preparation for tests in a PEM fuel cell, and to determine their electrochemically active surface area (ECSA). The electrochemical experiments are supplemented with microstructural analysis by SEM and XRD. Acknowledgement: This work has received funding from the European Union’s Horizon 2020 research and innovation programme under the Marie Skłodowska-Curie grant agreement No 764977. Additional support from the Generalitat de Catalunya (2017-SGR-292) and the Spanish Government (MAT2017-86357-C3-1-R and associated FEDER) is also acknowledged.

Exciton transfer using rates extracted from the "hierarchical equations of motion".

Frenkel exciton population dynamics of an excitonic dimer is studied by comparing the results from a quantum master equation involving rates from second-order perturbative treatment with respect to the excitonic coupling with the non-perturbative results from "Hierarchical Equations of Motion" (HEOM). By formulating generic Liouville-space expressions for the rates, we can choose to evaluate them either via HEOM propagations or by applying the cumulant expansion. The coupling of electronic transitions to bath modes is modeled either as overdamped oscillators for the description of thermal bath components or as underdamped oscillators to account for intramolecular vibrations. Cases of initial nonequilibrium and equilibrium vibrations are discussed. In the case of HEOM, initial equilibration enters via a polaron transformation. Pointing out the differences between the nonequilibrium and equilibrium approach in the context of the projection operator formalism, we identify a further description, where the transfer dynamics is driven only by fluctuations without involvement of dissipation. Despite this approximation, this approach can also yield meaningful results in certain parameter regimes. While for the chosen model, HEOM has no technical advantage for evaluation of the rate expressions compared to cumulant expansion, there are situations where only evaluation with HEOM is applicable. For instance, a separation of reference and interaction Hamiltonian via a polaron transformation to account for the interplay between Coulomb coupling and vibrational oscillations of the bath at the level of a second-order treatment can be adjusted for a treatment with HEOM.

Electrochemical studies on the corrosion resistance of Zn–Ni–Co coating from acid chloride bath

Anticorrosive deposits are a valuable approach to defending against corrosion from mild steel structures/machinery equipment. The Zn–Ni–Co coating has been deposited on low carbon steel surfaces using environment friendly optimized acidic chloride bath with ZnCl2·6H2O, NiCl2·6H2O, CoCl2·6H2O, sulphanilic acid (C6H7NO3S) and gelatin (C6H8O6). The standard Hull cell technique has been adopted for the optimization of bath components and experimental conditions, for the superior corrosion resistant coating. The corrosion test with potentiodynamic polarization method was performed to investigate the role of pH on the film quality and corrosion performances of the films. Further, the effect of current densities on corrosion resistance, thickness and hardness, have been investigated. Cyclic voltammetry technique has been used to test the electrochemical properties of the Zn–Ni–Co coating in acidic solutions. The results revealed that the increase in the current density favoured the increase in Ni and Co content in the deposit, showed higher corrosion resistance and higher cathodic current efficiency. The structural and morphological characteristics of the alloy coating have been obtained through scanning electron microscopy and X-ray diffraction techniques. The atomic force microscope was used to examine the topographic structure of the coating. X-ray Photoelectron spectroscopy was used to determine the chemical composition of alloy coatings and verified by energy dispersive X-ray analysis. The results indicate that a new and low-cost chloride bath for Zn–Ni–Co coating exhibit superior corrosion resistance properties and can be implement in various industrial applications such as automobiles, machine tools etc.

Optimization of High-Speed Electrolytic Plating of Copper Pillar to Achieve a Flat Top Morphology and Height Uniformity

Abstract Cu plating bath for high-speed electrodeposition of Cu pillar was designed in consideration of a flat top morphology of pillar and a pillar height uniformity. An ideal polarization curve was assumed for the flat top morphology. To obtain the ideal polarization curve, an effect of organic additive concentration and solution agitation on the polarization curve were investigated. The basic bath components were optimized considering a Wagner number to improve pillar height uniformity. To confirm the pillar top morphology and the pillar height uniformity, a 300 mm diameter wafer was plated with Cu at 20 A/dm2. As a result, improved pillar top morphology and pillar height uniformity were obtained. The optimized plating bath was applied to the plating of large-size panel of 415 × 510 mm.

Electrochemical Express Analysis of Organic Additives in Lead-Free Wafer Level Packaging Plating Baths

Semiconductor packaging migrated from wire bond to flip chip level interconnect to meet size, weight and electrical performance requirements. Lead-free alloys for flip chip attachment has become a common material in electronics. Alloys containing Sn and Ag as well as pure Sn are the most common ones. The mechanical strength, wetting, and fatigue resistance of these alloys and pure Sn is either comparable or surpass lead contained alloys. Electroplating with lead-free alloys is the most desirable technique due to its low cost and usefulness in building fine pitch solder bumps [1].The new generation of lead free plating systems targeting faster deposition rates, better uniformity with-in die and longer bath life. The co-deposition of elements may be complicated by the large difference in the electrode potentials of tin and alloying metals (e.g. silver, bismuth). To produce uniform and dense deposits, these plating baths include organic additives that are typically separated for two groups with different functions: polarizers that significantly affect the plating rate and control the uniformity of deposit; and grain refiners [2]. For desired properties of deposit, the bath components must be kept within specific concentration ranges. In some cases, the analytical results for bath components should be available more frequently in order to provide feedback to dosing system [3]. To develop most accurate and repeatable analytical methods, the interactions between lead free plating bath components were previously investigated and understood [2]. That allowed to develop efficient analytical techniques for analysis of lead free plating bath components. However, faster analytical methods are required for control of high speed plating baths. The effect of changes in the concentration of organic components on the structure of deposit were studied more recently and will be reported in this work.When the speed of analyses increases, it is critical to keep reproducible state of all electrodes. Therefore, new regeneration method for electrodes was developed. For development of new express analytical methods, we utilized an electrochemical cell with three electrodes connected to a potentiostat/galvanostat. RDE working and counter platinum electrodes were used as well as Ag/AgCl double junction reference electrode. It has been found that multiple factors can reduce the speed of electrochemical analysis. One of the most potent parameters that affect speed of analysis was a scan rate. Fig. 1 shows the electrochemical responses of polarizer at different scan rates.Other parameters and steps of analysis were also evaluated for potential reduction the analysis time. This presentation will provide more information related to the electrochemical behavior of organic additives at specific conditions when the analysis is performed with different speed. Results for other bath components will be also presented. The concentration of inorganic components and silver complexing agent can be determined via non-reagent and virtually real time spectroscopic analytical methods. The presentation will be concluded with a discussion of analytical results for several organic additives at different concentration levels.

Physical and chemical bases of decarburization of high-carbon ferromanganese melt

The aim of the work is to establish physicochemical patterns of behavior of carbon, silicon, manganese when using the method of oxygen purge of high-carbon ferromanganese. Method. The process of blowing red metal to sour is neglected. With the fusion of fused acid, it is more important to oxidize silicon. Its presence in metal is practical in the block of oxidized manganese. Because oxygen is an assimilation gas, the mixing processes of the converter bath components and the reduction of manganese oxides at the metal-slag interface do not develop properly during purging. The smelters of the medium-carbonaceous ferromanganese in the converter are characterized by a stable chemical warehouse and even a higher number of vimogs for this type of alloy. The low concentration of silicon in metal over a number of swimming trunks can be easily shoved with a hat of pre-purge bathtub with sour at the final stage of refining. The behavior of phosphorus in these smelts is not controlled. The content of P2O5 in the final slag is 0.1%. To achieve acceptable concentrations of phosphorus in the metal, it is necessary to use starting materials with a low phosphorus content. Scientific novelty.Taking into consideration the high affinity of silicon for oxygen, the physical and chemical basis for the production of medium-carbon ferromanganese, as well as metallic manganese and low-carbon ferromanganese, is the process of the interaction of manganese oxides of a certain basicity slag melt with silicon dissolved in ferromanganese (manganese), that is, as combined reduction -refining process to produce manganese ferroalloys with a given silicon content standard

The Multi-Functional Role of Boric Acid in Cobalt Electrodeposition and Superfill

Although alternative metals such as cobalt are becoming increasingly important as candidates for filling interconnects, questions remain regarding the role of boric acid, one of the primary bath components, in the electroplating process. This work demonstrates that boric acid has multiple functions in cobalt electroplating and superfill. Raman spectroscopy was used to determine speciation of boric acid in solution as a function of concentration and pH. Combining this with titration experiments, it was found that polyborate formation coincides with an increase in buffering capacity in the range of pH that is typical for cobalt electroplating. Atomic force microscopy and secondary ion mass spectrometry confirmed the correlation between hydroxide/oxide in the deposited film and the amount of boric acid in solution. Electrochemical experiments demonstrated that boric acid adsorbs to the electrode surface under certain conditions. Interconnect fill quality was also shown to be directly related to boric acid concentration. Boric acid is shown to be a necessary bath component due to its role in pH buffering and surface adsorption, affecting both blanket film plating and superfill of interconnects in the presence of a suppressor.