bluuebunny/crossref_metadata_2025_split huggingface dataset:
(Digital Presentation) Understanding Metal Additive Manufactured Surfaces
Authors: Stull Jamie A , Gorey Timothy , Clark Courtney L , Hooks Daniel E 
Published: July 2022

Metal additive manufacturing (AM) is being pursued as manufacturing technique in order to shorten development cycles and reduce cost through rapid iteration and agile design. Metal AM allows for designs that were not previously possible, optimizing the balance between mechanical strength and weight. However, rough as-built surfaces do not meet engineering specifications, with roughness measurements between Sa = 5 – 60 mm. Furthermore, depending on the build angle the surface roughness varies widely within a single part. These rough surfaces result in different surface morphology and chemistry compared to other manufacturing methods which has a direct impact on the susceptibility to localized corrosion and mechanical performance. This variation is also amplified depending on the machine used to build the material. We have extensively characterized the surface roughness, and corrosion response of AM 316L stainless steel (SS) that has been built on different machines which result in significantly different surface properties.
Our team is also developing environmentally friendly surface finishing techniques to reduce the surface roughness to meet specifications, increase corrosion performance, and drastically reduce the part-to-part variations. We have used optical methods to measure the surface roughness of as-built AM 316L SS, A20x (AM aluminum alloy), and Ti6-4. Aqueous and atmospheric corrosion measurements have been performed on 316L SS. Finally, EDS/SEM measurements reveal there is significant chemical segregation on the surface of the as-built material; however, surface treatment methods being developed by the group have been shown to remove this layer. Post-processing surface treatments result in a more homogeneous surface and improve the performance of the material.
(Digital Presentation) Effects of Surface Finish on the Corrosion Performance of Additively Manufactured Metals
Authors: Clark Courtney L , Stull Jamie A , Gorey Timothy , Hooks Daniel E 
Published: July 2022

Metal additive manufacturing (AM) is becoming a transformative technology in the manufacturing industry. The as-built surfaces produced by metal AM are very different compared to wrought material, typically resulting in very rough surfaces that have different corrosion properties. There are a large number of studies that have attempted to understand the corrosion response of metal AM. However, these studies are typically performed on materials that have been printed on a single machine. As a result, there are significant inconsistencies in the literature due to the high variability in the quality of parts manufactured on different machines. We will present work that compares the corrosion response of AM 316L stainless steel (SS) that has been printed on multiple machines. Our results have shown there is significant variability observed in the corrosion performance of metal AM parts built on different machines and within a single build plate. The observed corrosion performance is likely affected by the stability of the passive film, chemical segregation, and microstructure of the surface. We also propose that surface finishing of AM 316L SS reduces the part-to-part variations observed in the corrosion performance of the material printed on different machines and within a single build plate.
This talk will discuss the corrosion properties of AM 316L SS, A20x (AM aluminum alloy), and Ti-6Al-4V parts produced by direct metal laser sintering (DMLS). The majority of our work focused on understanding the susceptibility to localized corrosion of metal additively manufactured materials with respect to build machine, surface roughness, and build angle. As a result, we also examined the corrosion performance of 316L SS built on a single instrument as we varied the build parameters. Conventional electrochemical corrosion experiments were used to characterize corrosion performance, including open circuit potential, potentiostatic electrochemical impedance spectroscopy, and potentiodynamic polarization scans. White light interferometry, optical profilometry, scanning electron microscopy, and energy-dispersive X-ray spectroscopy were utilized to characterize the surface of the samples.
Corrosion-Resistant Sacrificial Metallic Coatings Produced By Cold-Spray for Al Alloys
Authors: Witharamage Chathuranga S , Alrizqi Mohammed A , Darwish Ahmed A , Nieto Andy , Gupta Rajeev Kumar 
Published: July 2022

Corrosion is a massive disaster in many sectors that caused the loss of billions of dollars. For example, it was reported that the total direct estimated cost of corrosion was about $ 276 billion in 1998 in the US, which is 3.1% of the nation’s GDP. Therefore, a necessity to develop methods to overcome this challenge arose in the last few decades. Thus, the development of corrosion resistive coatings is significantly attracted researchers' attention. In combination with the corrosion inhibitors, organic and conversion coatings are used to improve the corrosion resistance of high-strength Al alloys. However, many corrosion inhibitors are carcinogenic: Chromate conversion coating performed very well, but alternative options need to be explored due to restrictions on its applications due to the health and environmental regulations. Moreover, organic coatings provide good corrosion resistance, but poor wear resistance and mechanical damage lead to corrosion issues. Metallic coatings are an alternative, and galvanized steel is one of the prominent examples. However, metallic coatings produced by elements such as Cr, Ni, Ti, or Ta are noble for Al or Mg-based alloys. Therefore, in any event of coating breakdown, the substrate would be more active and act as an anode and, corrode rapidly by galvanic interaction. Thus, such metallic coatings produced by the above-mentioned corrosion resistance elements are not very attractive for Al alloys.
We present a sacrificial metallic coating with outstanding corrosion resistance. Al was alloyed with V using high-energy ball milling (HEBM) which enabled the formation of a superstrated solid solution of V in Al. Al-V alloy powder produced by HEBM was used for coating the high-strength substrate using cold spray. The corrosion behavior and corrosion mechanisms of cold sprayed specimens were investigated using advanced electrochemical and analytical techniques. The cold sprayed specimens exhibit high pitting potential, low corrosion current density, and a less noble corrosion potential than the substrate. This indicates that in any event of coating breakdown, the coating would corrode (i.e., act as a sacrificial anode) and prevent the substrate from corrosion. Alloy composition is chosen such that corrosion of coating releases chemical species that could inhibit corrosion by decreasing the cathodic efficiency of the substrate.
(Digital Presentation) Effect of Zirconium Addition on the Corrosion Behavior of Binary Magnesium-Zirconium Alloys
Authors: Chen Yi-ting , Chu Peng-Wei 
Published: July 2022

Magnesium (Mg) has the characteristics of low density and high specific strength, but its poor corrosion resistance is a fatal disadvantage. Therefore, various alloying elements are often added to Mg alloys to improve their properties. Among them, zirconium (Zr) is commonly added as a grain refiner for Mg alloys. However, in most cases, Zr was added as a secondary additive, by which the effect on the corrosion properties would be shadowed by other alloying elements. Therefore, this research aims to elucidate the effect of Zr addition on magnesium corrosion with two binary Mg-Zr alloys with different Zr concentrations (0.037wt% and 0.208wt%).
In this study, scanning electron microscope (SEM) with X-ray energy dispersive spectroscopy (EDS) was used to study the Zr distribution and compositional difference in the alloys. Scanning Kelvin probe force microscope (SKPFM) was used to reveal the Volta potential difference between the Zr particles and the Mg matrix. In situ optical microscopic (OM) observation combined with open circuit potential (OCP) monitor was used to record the alloy corrosion morphology evolution. And through electrochemical impedance spectroscopy (EIS) analysis, the difference in the alloy corrosion properties was investigated. Hydrogen evolution tests were used to quantify the corrosion rates.
Through SEM/EDS analysis, the size, distribution, and Fe content of the zirconium particles in the alloy are the most important differences between the two samples. For the sample with 0.208wt%Zr, the Zr particles are larger and contain more Fe. From SKPFM analysis, we also found that the Volta potential difference between the Zr particles and the Mg matrix is larger for the sample with higher Zr addition. Hydrogen evolution tests show that the corrosion rate of the 0.208wt%Zr sample is about 5 times compared to the 0.037wt%Zr sample, which is consistent with the EIS analysis results. The driving force of corrosion mainly comes from the microgalvanic effect provided by the Zr particles. The relationship between the Zr particles and localized corrosion behavior will also be discussed.

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(Invited) Metrology of Solution Processable 2D Materials for Electronic Applications
Authors: Lopinski Gregory 
Published: July 2022

Two-dimensional materials have attracted intense interest due to their remarkable physical and electronic properties as well as their potential for a diverse range of applications. Many of these envisaged applications (i.e. printed/flexible electronics, energy storage, photovoltaics) require single or few layer flakes of a 2D material that can be dispersed in solution to facilitate deposition onto a substrate, formulation into an ink and/or mixing into a composite. A variety of powders and dispersions claiming to contain 2D materials such as graphene are now becoming available but the variable quality of these materials and lack of standardized protocols for their assessment is hampering the development of applications.
Here we will describe ongoing work at the NRC aimed at developing characterization methods and standard protocols to characterize graphene and graphene oxide (GO) powders, dispersions and inks. We employ a variety of experimental techniques including scanned probe microscopies (AFM and STM), vibrational spectroscopy (Raman and FTIR), X-ray diffraction, X-ray photoelectron spectroscopy and dynamic light scattering in order to characterize the structure and chemical composition of in-house and commercially available materials. These methods allow us to measure key parameters to assess material quality such as flake thickness and lateral size, carbon to oxygen ratio and impurity content. Conductivity and work function of ultrathin films produced from various graphene and graphene oxide containing dispersions have been also measured. The performance of these films as transparent conductors can be characterized by a figure of merit based on the optical transmission and conductivity of the film. Performance of films made via reduction of GO will be compared with those based on graphene exfoliated without oxidation.
Recently we have begun to extend this work to dispersions of other two-dimensional materials such as the transition metal dichalcogenides (TMDC). Initial characterization of commercially available TMDCs will be presented.
Detection of Proton Carriers in Tyrosine-Rich Peptide Thin Film
Authors: Yoon Jeong Hyun , Song Min-Kyu , Kwon Jang-Yeon 
Published: July 2022

Traditional Von Neumann structure, where memory and computational units are separated, is now facing significant difficulties in terms of power consumption and computing speed in big data era. Therefore, human brain-like computing architecture is now paid attention in research field owing to its high parallelism, fault tolerance and robustness1-2. In this biological system, synaptic weight which plays crucial role in memory and learning is modulated by ionic species, especially protons transmitted between synapses. Here, we focused on short length peptide Y7C (YYACAYY) thin film which induces proton coupled electron transfer (PCET) due to its Tyrosine-rich structure. The Y7C film has shown an interesting behavior in which electrical conductivity varies with humidity3-4. By this modulation, bimodal memristor using both of voltage and humidity5 input and synaptic transistor which shows dynamic reponses through humidity have been demonstrated, but direct relation between current and proton conduction is still ambiguous. Therefore, we measured transient current flow between Pd and Au electrode and detected proton conduction of Y7C film.
In previous studies, voltage & humidity controlled Y7C bimodal memristor has been reported. However, since the current regulation through humidity showed insufficient response than that through voltage, a definite relationship between moisture and current needs to be defined. To achieve that, thin film of the peptide material dissolved in Trifluoroacetic acid (TFA) 99% solution was spin coated on SiO2/Si substrate. By measuring the transient current of the Y7C film, presence of temporary charge carriers was observed. Also, the electrical impedance spectroscopy (EIS) of peptide layer showed a semicircle and a nonvertical tail, which indicate ionic conduction through the film. Lastly, film characterization of Y7C thin layer unveiled that the corresponding ions are protons as originally targeted. This research has showed principles of peptide thin film’s current increment driven by both of humidity and voltage through electrochemical reaction.

Fig.1.
Transient charge flowing through Y7C thin film measured in various atmospheric conditions and electrodes

Acknowledgment

This work was supported by the National Research Foundation of Korea (NRF) grant funded by the Korea government (MSIT) (No. 2020R1A2C2004864).

References

Pakkenberg B, Pelvig D, Marner L, Bundgaard M J, Gundersen H J G, Nyengaard J R and Regeur L 2003 Exp. Gerontol. 38 95

Abbott L F and Nelson S B 2000 Nat. Neurosci. 3 1178

Lee, Jaehun, et al. "Proton conduction in a tyrosine‐rich peptide/manganese oxide hybrid nanofilm." Advanced Functional Materials 27.35 (2017): 1702185.

Sung, Taehoon, et al. "Effects of proton conduction on dielectric properties of peptides." RSC advances 8.59 (2018): 34047-34055.

Song, Min-Kyu, et al. "Proton-enabled activation of peptide materials for biological bimodal memory." Nature Communications 11.1 (2020): 1-8.

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Plasma Charge Carrier Attachment Induced Transport in Solid Ionic Materials
Authors: Weitzel Karl-Michael , Wiemer Jan L. , Schäfer Martin 
Published: July 2022

Lithium aluminum germanium phosphate of the stoichiometric formula Li1.5Al0.5Ge1.5(PO4)3 has been studied by means of the femtosecond laser plasma charge attachment induced transport (fs-plasma CAIT) [1]. The technique is based on attaching polarity selected charge carriers from a plasma to the front side of a sample, which induces transport of mobile charge carriers in the bulk of this sample. First, in a conductivity study, an activation energy of 0.73 eV for lithium ion transport has been measured by means of proton attachment. Second, a constant-voltage attachment experiment employing deuterium ions has been performed and subsequently analyzed by time-of-flight secondary ion mass spectrometry. The resulting concentration depth profile revealed a replacement of native lithium ions by deuterons in the first 350 nm of the sample. A theoretical analysis of the profile by means of the Nernst−Planck−Poisson equations provides access to the concentration dependent diffusion coefficient and the unique site energy distribution of the natively contained lithium ions. A full width at half-maximum of 113 meV for the SED of the Li+ ions is determined. The approach discussed can be applied to many more materials, where the potential energy landscape affects the function.
More recent efforts in studying solid state ionic materials by means of the Plasma-CAIT technique will also be presented.
[1] Jan L. Wiemer, Martin Schäfer, and Karl-Michael Weitzel, J. Phys. Chem. C, 125, 4977−4985, (2021)

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(Invited) Combining Machine Learning, DFT, EFM, and Modeling to Design Nanodielectric Behavior
Authors: Schadler Linda S , Chen Wei , Brinson L. Catherine , Sundararaman Ravishankar , Prabhune Prajakta , Iyer Akshay 
Published: July 2022

Polymer Nanodielectrics are class of materials with intriguing combinations of properties. Predicting and designing the properties, however, is complex due to the number of parameters controlling the properties. This makes it difficult to compare results across groups, validate models, and develop a design methodology. This presentation will share a recent approach to developing a data driven design methodology grounded in physics-based models and experimental calibration. We combine finite element modeling of dielectric constant and loss functions with a Monte Carlo multi-scale simulation of carrier hopping to predict break down strength. Filler dispersion, filler geometry, isotropy and interface properties are explicitly taken into to account to compute objective functions for ideal nanodielectric insulators. Further, we have used machine learning to develop an EFM technique for directly measuring the dielectric constant of the nanoscale interfacial region as critical input to our models. Ultimately, we calculate the Pareto frontier with respect to nanocomposite constitute properties and geometry to optimize properties.
The finite element approach can be used to forward predict properties based on the properties of the interfacial region and filler dispersion, or as an inverse tool to calculate interface properties or develop optimized filler morphologies. The breakdown strength model critically depends on the energy distribution of trap states that inhibit space charge motion. We have developed an ab initio approach to determine the trap states at amorphous interfaces, and have used that to do a systematic analyses of trap distributions in composites with functionalized particle interfaces. The models all use 3D particle distributions based on 2D imaging (TEM) of the composites and publicly available tools for binarization and characterization of filler morphology. Finally, we use a design of experiment approach (Latin Hybercube Design) to sample the complete experimental design space, and using calibrated models and morphologies, create a data set spanning the full set of parameters. We use the data from the DOE to train a Gaussian Process metamodel and a genetic algorithm to determine which designs fulfill the design parameters. The talk will present several case studies as examples.
The data for this work was accessed from a new data resource, MaterialsMine, using FAIR (Findable, Accessible, Interoperable, and Reusable) principles. MaterialsMine is an open source data repository, and resource. It includes unique visualization tools as well as modeling and characterization resources.
(Invited) Nanocrystalline Oxide-Based Luminescent Nanophotonic Structures
Authors: Serna Rosalia , Gonzalo Jose , Mariscal-Jimenez Antonio , Gomez Rodriguez Pilar , Caño Andres 
Published: July 2022

Light nanoemiters are the cornerstone of photonic integrated applications including displays for consumer products such as phones and smartwatches, and for advanced application such as quantum emitters. In this context it is appealing to have access to a single material platform suitable for tunable wavelength emission, and if possible, that can provide broadband white light emission. Solid state light emitting nanostructures based on Europium ions are a promising solution. When imbedded in a solid they can have two oxidation states Eu3+ or Eu2+ which upon excitation show a either a high purity red emission (associated to the Eu3+ dipole-forbidden intra-4f shell 5D0® 7F2 transition), or a broad emission band in the 450-600 nm spectral region (related to the Eu2+ dipole-allowed 4f6 5d -> 4f7 transitions). Here I will discuss the strategy that our group is following based on europium oxides EuOx, 1/3<x<1, as this approach allows to have a high density of emitters. Moreover, their electric and optical properties can be tuned from the sesquioxide Eu2O3 that is a wide bandgap dielectric that shows the Eu3+ ion related narrow band red emission, to the monoxide EuO that is a semiconductor that shows a wide band white light emission related to the Eu2+ ion. For the nanoemitters we have prepared EuOx nanocrystalline films with high transparency, and in which the coexistence of both oxidation Eu states enables wavelength tunability [1.2]. Finally, recently we have designed 2D hybrid nanoemitters by integrating the EuOx films with metallic metasurfaces in order to induce an enhancement of the emission intensity by selective plasmonic excitation [3].
[1] A. Mariscal, A. Quesada, A. Tarazaga Martín-Luengo, Miguel A. García, A. Bonanni, J.F. Fernández and R. Serna, Appl. Surf. Science 456,980 (2018).
[2] A. Mariscal-Jiménez, A. Tarazaga Martín-Luengo, B. Galiana, C. Ballesteros, A. Bonanni, J. Martín-Sánchez, R. Serna, J. Phys. Chem. C. 124, 15434–15439 (2020).
[3] P. Gomez-Rodriguez, E. Soria, Y. Jin, A. Caño, I. Llorente, A. Cuadrado, A. Mariscal-Jiménez, A. K. Petford-Long, R. Serna and J. Gonzalo, Nanophotonics. 10, 3995–4007 (2021).
(Invited, Digital Presentation) Quantum Dots Based Transparent Light Emitting Diodes
Authors: Chrzanowski Maciej , Witczak Łukasz , Podhorodecki Artur 
Published: July 2022

Colloidal quantum-dot light-emitting diodes (QLEDs) have attracted considerable attention in the optoelectronic industry due to their
remarkable performance, which makes them promising candidates for displays and lightning technology with a particular emphasis on color purity, brightness, and emission tunability. For these reasons over last few years a very impressive progress has been obtained in this research area in terms of improvement of QLED external quantum efficiency, their brightness and lifetime.
While the race to improve the parameters of key importance for the operation of the QLED continues and QLEDs will be probably commercially available soon, the other topics related with QLED devices are at much less advanced level. This includes for example development of flexible, transparent or printable QLED devices or preparation of QLED devices in air.
In this paper we will present our results related with flexible and/or transparent QLED devices obtained from green Cd-based quantum dots. We will discuss optical and electrical properties of QLED devices when using as transparent, conductive electrodes PMA/Ag, MoOx/Au/MoOx or silver metal-mesh fabricated by Ultra Precise Deposition (UPD). We will also describe thin-film deposition methods such as spin-coating/sputtering or inkjet-printing as a new versatile approach towards fabrication of flexible transparent electronics.