bluuebunny/crossref_metadata_2025_split huggingface dataset:
Investigating Magnesium Ion Intercalation in WS2 Cathodes
Authors: Houghton Todd , Nandy Mayukh , Modi Arjun , Swaminathan Srivatsan , Yu Hongbin 
Published: December 2020

Due to an unmatched combination of energy density, power output, and charge/discharge stability, lithium-ion batteries remain the energy storage technology of choice for a diverse and growing ecosystem of electronic devices, from mobile phones to electric vehicles. However, as the number of applications continues to rise, limitations of Li-ion concerning achievable capacity, cost, and environmental pollution have become increasingly apparent. Divalent Mg-ion chemistries present an intriguing alternative to lithium; however, studies of sulfur-containing chalcogenide cathodes reveal no clear path to commercial adoption. MoS2 and Chevrel-type cathodes do not currently meet anticipated energy density targets, while TiS2, Ti2S4, and Chevrel compounds use volatile electrolyte solutions.
While exhibiting an atomic structure and interlayer spacing similar to TiS2 and MoS2, the electrochemical properties of WS2 cathodes remain largely unexplored in the context of Mg-ion intercalation. Here, we study a magnesium ion half-cell constructed from mechanically flexible materials, chosen for their low cost, simple fabrication steps, and separator-free reaction chemistry. Cathodes were fabricated from WS2 powder and electrolyte binder, while a polymer-based electrolyte made of PVDF-HFP and magnesium perchlorate dissolved in ethylene carbonate/propylene carbonate was chosen for its high ionic conductivity and low volatility. Analysis using cyclic voltammetry shows a reversible redox reaction involving Mg species at the cathode/electrolyte interface, indicating presence of an intercalation reaction. Additional cathode surface data is provided by XPS, Powder XRD, and Raman spectroscopy. Cell fabrication details and analysis of reacted cathodes in the context of Mg intercalation will be discussed.
(Invited) Effect of Cr Concentration on Dissolution of (Mn,Cr)S Inclusions in Stainless Steel
Authors: Nishimoto Masashi , Muto Izumi , Sugawara Yu , Hara Nobuyoshi 
Published: December 2020

The pit initiation sites for commercial stainless steels have been attributed to sulfide inclusions such as MnS. The chemical composition of the inclusions affects the pitting corrosion resistance of stainless steels. In general, MnS inclusions in stainless steels contain a small amount of Cr, and thus they are accurately written as (Mn,Cr)S inclusions. It has been reported that Cr in (Mn,Cr)S inclusions have an inhibitory effect on the dissolution of the inclusions. However, the extent to which the Cr concentration in the inclusions prevents the dissolution of the inclusions remains unclear. In this study, spark plasma sintering was used in the facile fabrication of stainless steel specimens containing artificial (Mn,Cr)S inclusions with different Cr concentrations.1 A microelectrochemical technique was applied to elucidate the effect of Cr concentration on the dissolution of the inclusions in stainless steel.
Type 304 stainless steel powders were mixed with either MnS or Cr2S3 powders to prepare sintered specimens containing 0.06 mass% S. The mixed powders were loaded into a cylindrical graphite die and subsequently compressed into a pellet. The pressed compact was sintered under vacuum conditions and uniaxial pressure in a spark plasma sintering system. The sintered specimens were ground with SiC papers and then polished with diamond pastes. Potentiodynamic polarization was conducted in naturally aerated 0.1 M NaCl (pH 5.5) at 298 K. The specimen surface was masked to make an electrode area of approximately 100 µm × 100 µm containing a single artificial inclusion. All the potentials reported in this study refer to the Ag/AgCl (3.33 M KCl) electrode (0.206 V vs. standard hydrogen electrode at 298 K). During polarization, the electrode area was observed using an in situ real-time optical microscopy system.2

The anodic polarization curves were measured to analyze the dissolution and pit initiation behavior of the artificial (Mn,Cr)S inclusions. The onset potential of inclusion dissolution and the pitting potential increased with increasing Cr concentration in the inclusions. The onset potential of inclusion dissolution reached approximately 0.7 V when the Cr/(Mn+Cr) atomic ratio in the inclusion was more than 0.5. This potential is almost the same as the transpassive region of Type 304 stainless steel. There was not much difference even if the Cr/(Mn+Cr) ratio of the inclusions was higher than 0.5. We concluded that the inhibitory effect of Cr on the dissolution of (Mn,Cr)S inclusions is most effective when the Cr/(Mn+Cr) ratio is 0.5.
References:

M. Nishimoto, I. Muto, Y. Sugawara, and N. Hara, ISIJ Int., 60, 196-198 (2020).

A. Chiba, I. Muto, Y. Sugawara, and N. Hara, J. Electrochem. Soc., 159, C341-C350 (2012).
(Invited) Rapid Photo-Charge Mapping of Stainless-Steel Under the Hydrogen Permeation
Authors: Azumi Kazuhisa , Masaki Hiroto , Baba Kazuhiko 
Published: December 2020

Photocurrent techniques have been applied to analyze the properties of passive films on metals and their corrosion phenomena. Photocurrent mapping is also used to evaluate the inhomogeneity of, for example, non-uniform corrosion behavior by using a lock-in amplifier to detect a weak photocurrent signal combined with a laser light scanning. This method is, however, takes a long time to acquire a scanning image due to a rather slow time-constant of the lock-in amplifier measurement. In this work, a photo-charge mapping method is developed in which an intense UV laser pulse light (405 nm, 0.5 W in the present study) is focused on the specimen surface and a photo-charge evolved by a single laser pulse is evaluated by integrating the photocurrent using an electronic integrator, as shown in Fig. 1. An intense laser pulse provides a large photocurrent in some condition sufficiently for a single photocurrent pulse analysis. Fast scanning of the laser light is also achieved by using a galvano-scanner. Currently, a time required for one image acquisition is a few minutes which is limited due to the software execution time.
In this work, the spatial distribution of hydrogen permeation in a stainless-steel sheet (SUS304, 0.1 mm in thickness) placed in a Devanathan cell was traced under the tensile stress test. Hydrogen was introduced from the backside of the sheet by using the galvanostatic cathodic polarization at –1mA cm–2, and penetrated hydrogen to the front side was oxidized under the anodic polarization at +0.8 V vs. Ag-AgCl R.E. The passive film was pre-formed before the hydrogen penetration. Absorption of hydrogen into stainless steel caused a drastic increase of photocurrent on the n-type semiconductor passive film due to the photo-assisted oxidation of permeated hydrogen atom via a stainless-steel sheet, i.e., hydrogen atoms can be effectively oxidized by the holes generated by UV irradiation in the passive film. In the photo-charge image shown in Fig. 1, left half of the observed area (4mm x 4 mm, 40 x 40 pixel) was penetrated by hydrogen from the backside where the increase of photo-charge was observed.
The Devanathan cell was combined with a tensile tester, and a photo-charge map was traced during the hydrogen loading under the loading condition until the notched sample was cleaved. The photo-charge intensity increased around the notch before cleavage, probably due to an increase of hydrogen concentration penetrated or thickening of the passive film.

Figure 1
(Invited) Radiolysis and Corrosion of Stainless Steel in High Temperature Water Environment
Authors: Feron Damien , Wang Mi , Corbel Catherine , Perrin Stephane 
Published: December 2020

This paper focus on the corrosion behaviour of austenitic 316L stainless steel in PWR primary water under the influence of radiolysis, including experimental devices and main obtained results.
After a short overview of the literature in the field, the approach is described with the use of a high energy proton beam to control the production of radiolytic species at the interface between stainless steel (316L type) and PWR water solution in a high temperature and high pressure electrochemical cell working up to 300°C and 100 bar.
The corrosion potential of stainless steel was enhanced by the radiolysis causing by high energy proton beam. A high similarity of electrochemical behaviour was also observed under electron beam. The electrochemical oxidative response of the 316L/PWR solution interface under radiolysis is related to the surface characterization analysis (SEM, XPS, Raman spectroscopy, NRA...) on the oxide layers of 316L which are formed under or without irradiation. The radiolysis effect on the oxide film includes micron scale cavities which were observed in a highly irradiated oxide film. The observation of a-Fe2O3 hematite on the outer oxide film where cavities were formed is in accordance with the electrochemical oxidative response.
Radiolysis influences not only the electrochemical behaviour but also the oxide formation of stainless steel in high temperature water environments, like primary water of Pressurised Water Reactors (PWR).
(Invited) Admittance Analysis of Passive Film on Rebar in Solution Simulating Concrete Pore Water
Authors: Inohira Kanaho , Hoshi Yoshinao , Watanabe Hikari , Shitanda Isao , Itagaki Masayuki 
Published: December 2020

Steel corrosion is suppressed in concrete because the passive film is formed on the steel surface of rebar owing to the strong alkaline environment inside the concrete. Dawson et al. [1] reported that the corrosion state of steel rebar in concrete can be evaluated by the charge transfer resistance, R
ct, estimated from impedance spectrum. In order to estimate R
ct from impedance spectrum, they [1] proposed an equivalent circuit which includes the solution resistance R
sol, R
ct, electric double layer capacitance C
dl, and Warburg impedance Z
w. An interfacial resistance at rebar/concrete interface was defined as R
ct in the report [1], whereas the authors consider that this interface resistance should be a passive film resistance R
f when passive film is formed on rebar and the interface resistance is very large. It is often difficult to estimate R
f under conditions where the passive film is formed on the rebar surface of the rebar because the impedance locus in the low frequency range does not converge to the real axis of Nyquist plane due to the large value of R
f. In this study, the precise determination method of R
f by the admittance is proposed.
The electrochemical impedance measurement was carried out by a three-electrode system. A rod of carbon steel was adopted as a working electrode. The carbon steel used in the present study has the same composition as rebar which is normally used in actual reinforced concrete structures in Japan. A platinum wire and a saturated KCl silver/silver chloride electrode were used as counter and reference electrodes, respectively. A potentio/galvanostat (Solartron, 1287) and a frequency response analyzer (Solartron, 1255B) were used as measuring devices. In the impedance measurement, the measurement frequency range was from 10 mHz to 10 kHz, the DC potential was corrosion potential, and the AC potential amplitude was 10 mV. A saturated calcium hydroxide solution was used for the test solution to simulate the concrete environment. The pH of test solution was about 12.5.
The impedance spectrum of rebar described a part of semicircle on Nyquist plane. Because the impedance locus in the low frequency range did not converge to the real axis, it is necessary to extrapolate a semicircle from the partial semicircle for the estimation of R
f. The plots of admittance showed a clear semicircle and converged to the real axis in the low frequency range. As high and low frequency limits of admittance correspond to 1 / R
sol and 1 / (R
sol + R
f), respectively, on the real axis of the complex plane, the R
f can be estimated directly from the plots of admittance on the complex plane. The present results suggested that the proposed method can be applied to estimate R
f of rebar in concrete more accurately.

Reference

[1] J. L. Dawson, L. M. Callow, K. Hladky, and J. A. Richardson, Proceedings of
NACE Corrosion/78, Paper No. 125 (1978).
Investigation of Electrochemical Corrosion of SS316L in Different Electrolyte
Authors: Masud Jahangir , Thakare Jivan , Martin Chris 
Published: December 2020

Corrosion is defined as the destruction of metals and alloys by chemical or electrochemical reaction with its environment. The corrosion occurs because of the normal trend of metals to come back to their thermodynamically stable native state. Corrosion cannot be avoided, but it can be controlled and prevented by using suitable methods like cathodic protection, anodic protection, metallic coating, alloying and using inhibitors, etc. Of these, the application of inhibitors reduces the aggressiveness of the corrosive and unsafe aqueous surroundings and preventing the metal and alloy from corrosion by forming a protective layer over the metal surface. The corrosion behavior of stainless steel and other metals in seawater has been studied by many researchers [1-2]. Stainless steels (316L) have been used successfully in many applications in the marine environment. 316L is considered to be one of the most resistant of stainless steel under marine environments, and it has excellent mechanical properties at elevated temperatures and easy fabricability. It is an important structural material for many industrial units, especially the desalination plants. 316L is the most likely candidate for saline environment applications due to their excellent corrosion resistance.
The present work was undertaken to study the corrosion behavior of SS 316L metal in different mediums such as Seawater and calcium chloride (Fig. 1) solution by polarization study. The effect of oxygen or air in the electrolyte solution will also be investigated. Corrosion parameters such as corrosion potential, corrosion current, linear polarization resistance, and corrosion rate will be compared and presented in the meeting.
References
[1] Baoping Cai et al., Corrosion Science 52 (2010) 3235–3242
[2] Yong Cui et al., Water Research 88 (2016) 816-825

Figure 1
Influence of Thermomechanical Loads on the Corrosion Behavior of Metal-Polymer-Joints
Authors: Gundlach Christian , Stach Thomas , Menzel Marcus , Dilger Klaus , Hartwig Sven 
Published: December 2020

Metal-polymer-joints can be found in multiple today’s major applications like in hybrid car parts in terms of lightweight construction or molded electrical contacts for high-voltage applications. Common to both is the harsh environment they are exposed to including elevated temperature changes inducing thermomechanical stresses based on the differences of the CTE values as well as corrosive media like salty water, solvents or electrolytes. Each promotes its own corrosion mechanism that in most cases comes along with a degradation of the material’s and therefore the part’s performance in service. Especially, two mechanisms have to be considered when dealing with corrosion of metal-polymer-joints. Firstly, corrosion processes of metal and polymer can influence each other as well as the metal-polymer interface layer depending on the material combination. Secondly, thermomechanical stress due to temperature changes can also have an effect on the material’s corrosion behavior. Studying both mechanisms would help to improve the service time of hybrid parts.
The work introduces a new method to investigate corrosion processes in metal-polymer-joints combining the influence of corrosive media and thermomechanical load. A hybrid specimen consisting of a specially formed metal inlay fully surrounded by a potting polymer is used for the measurements. When exposed to cyclic temperature load in a test chamber mechanical stress is induced in the polymer due to the different CTE of the materials. For the measurements typical material combinations used in lightweight construction and high-voltage applications are used. The hybrid specimens are exposed to thermal shocking cycles while being fully surrounded by corrosive media. Throughout the experiment, the specimens are constantly monitored using electrochemical impedance spectroscopy (EIS). In addition, a visual inspection of the specimens takes place after certain times to analyze the overall condition and possible cracks. As a reference, the same setup is applied only to the metal inlays used in the hybrid specimens. By interpreting the results of the EIS measurements, possible corrosion processes of metal and polymer as well as their correlation can be characterized in detail. Additionally, the comparison of hybrid specimens and raw metal inlays reveals the influence of the thermomechanical load on the corrosion process. The experimental part is supported by FE-simulations, which are also supplementary presented in this investigation.
Thermal Isotropic Atomic Layer Etching of Metallic Molybdenum
Authors: Fischer Andreas , Routzahn Aaron , Lill Thorsten 
Published: December 2020

In high aspect ratio structures such as 3D NAND stacks, high-k oxides or certain metals need to be removed from sidewalls and even non-line-of-site locations where access via reactive ion etching would be challenging or impossible. To achieve etching in these locations, thermal processes need to be applied that lack any intrinsic directionality and are therefore isotropic. Thermal Atomic Layer Etching is one option to facilitate this kind of process. Therefore, it has gathered significant attention recently and is now being explored in academia and industry.
In this work, we demonstrate isotropic Atomic Layer Etching on metallic molybdenum using a three-step process that involves oxygenation of the metal surface, a conversion reaction using boron-trichloride followed by a hydrogen-fluoride clean step. We measured the etch rate per cycle to be around 10 Å with low temperature dependence in the range between 150°C and 250°C.
Furthermore, we examined the effectiveness of various oxygenation methods on the surface of metallic molybdenum films. These methods included thermal oxygenation as a function of temperature, oxygenation by a remote plasma and in-situ plasma fluorination. We established that an oxygenation level of more than 70% as measured with XPS is needed in order for the ALE process to work. Levels in this range could be achieved via in-situ plasma oxygenation as well as with a remote plasma. Thermal oxygenation, on the other hand, required substrate temperatures in access of 400°C to oxygenate at the 70% level.
In this study we also show an example of molybdenum ALE in an application that involved the removal of this metal from a 50:1 aspect ratio 3D NAND structure. We measured etch rates on vertical and horizontal surfaces as well as the depth dependence in removal rate of molybdenum.
The Metal Gate Cut Process Development
Authors: Ji Shi-liang , Han Qiu-Hua , Zhang Hai-Yang 
Published: December 2020

The technology of FinFET has led to the continuity of device scaling and enabled the prolongation of Moore’s Law towards the 7 nm and beyond nodes. The gate cut last has been widely adopted since it can provide better SiP/SiGe growth environment, hence yielding the better electrical performance. However, this approach requires more complex process engineering at 3D structure. Both perfect physical structure and good electronic performance are challenging for gate cut last process.
As is well known, the metal gate cut process is the only choice of 5nm FinFET and GAA FinFET, which directly determines the performance of FinFET. At present, the metal gate cut process has suffer the following difficulties: the Critical Dimension of the metal gate is only about 20nm, the height is over 100nm, and the aspect ratio has exceeded the limit of the most advanced etching tool; the metal gate complex composition, including more than 10 kinds of metal and insulation materials; the cut CD is very small, but the profile requirement is very challenging, all the metal layers are vertical, and the same CD is maintained from top to bottom. The bigger challenge is that the line end of metal gate cut is very close to germanium silicon or phosphor silicon. On the other hand, the metal's easy collection of charge and conduction will greatly increase the plasma induce damage risk, which needs to be controlled by properly selecting photo and etching conditions.
We will start a study on the above issues and discuss the development direction and research ideas in each aspect. This manuscript will focus on plasma etching development during metal gate cut process. The CD shrinkage is very critical process in the soft mask etching process so as to break through the exposure limit of the immersion lithography. In general, immersion lithography with negative photoresist can not complete less than 40 nm CD, but gate cut, especially metal gate cut CD need as small as 20 nm. This puts forward very high requirements for soft mask etching. On the one hand, etch stop or defect cannot be caused with the large CD shrinkage; on the other hand, the CD should meet the design requirements and the patterning should be complete. We use the CxHyFz as etching gas with the advanced coupled plasma etching tool.We found the high/low bias pulsing scheme can reach balance on all sides, as the CD shrinkage, defect control, pattern transfer, line width roughness, the optimum process window. Another part will focus on metal cut etching process, cycle model is benefit to so many kinks of materials. Vertical profile show trade-off and ILD loss, we found the different design and requirement need to adopt different ILD remaining approach. At the same time, low Te etch process is key to avoid plasma induce damage.
In Situ Deposition of Platinum-Group Metals for Electrocatalytic Hydrogen Peroxide Production By Oxygen Reduction
Authors: Wang Yu Lei , Gurses Sadi , Felvey Noah , Bayoglu Ozge , Kronawitter Coleman X 
Published: December 2020

Hydrogen peroxide (H2O2) is a valuable commodity chemical that serves as a disinfectant for a number of important chemical end-use applications and as an oxidant for a several emerging technologies for oxidative chemical transformations. Recently there has been a resurgence of interest in the electrocatalytic production of H2O2 by oxygen reduction because it has been recognized to be compatible with the general concept of distributed chemical manufacturing, which in many cases presents strategic advantages over conventional operations based on centralized, large-scale systems. When compared with conventional synthesis technologies, electrocatalytic production of H2O2 – which uses only air, water, and electricity as inputs – is amenable to greater geographic distribution and shows strong potential to be cleaner and more sustainable.
This presentation will describe efforts to utilize platinum-group metals as electrocatalysts for the cathodic reduction of O2 to H2O2 in water. Platinum-group metals are prototypical fuel cell catalysts and generally regarded to be non-selective to H2O2. The presented results will show that in certain electrodeposition synthesis conditions, these metals can form the basis of engineered electrodes that are both highly selective and active for cathodic H2O2 production by oxygen reduction. The use of these metals presents an engineering advantage because they are acid-stable, and therefore (1) compatible with existing PEM fuel cell cathode environments and (2) produce H2O2 in the low-pH environment where its stability is maximized. This presentation will discuss the physical, structure, and chemical properties of electrocatalysts that correlate with high H2O2 selectivity, and the fundamentals of the electrodeposition technique by which they are synthesized.