bluuebunny/crossref_metadata_2025_split huggingface dataset:
Environmental Aspects of Using Metallic Organic Frameworks As Adsorbents in Natural Gas Storage Systems
Authors: Abd Elhamid Mahmoud Hassan , Dailly Anne , Cai Mei 
Published: February 2020

The use of natural gas (NG) for automotive industry has gained renewed interest due to its growing supplies in the United States, relatively low cost compared to gasoline and diesel fuels and reduced emissions of carbon and particulate per equivalent. Because of its relatively low energy density NG must be stored at high pressure, 3,600 psi service pressure in the United States, in order to achieve an energy density suitable for vehicular use. Compressed NG cylinders are available in four types. Type 1, all metal (steel or aluminum) are the most widely used CNG cylinders in the world. Type 2 cylinders are metal liner reinforced by composite wrap (glass or carbon fiber) around the middle. Metal liner reinforced by composite wrap around the entire tank constitutes Type 3. While Type 4 cylinders are made of plastic gas-tight liner reinforced by composite wrap around the entire tank. Utilization of CNG storage systems in light duty vehicles has limited market penetration because of the cost of the pressure vessel and its occupancy of cargo space.
Adsorbents materials are becoming an attractive option to develop low pressure and conformable NG storage system. Adsorbed NG storage relies on physisorption, i.e. weak gas-solid interactions between the fuel and the adsorbent surface. While research into adsorbents has focused on assessing their storage capabilities there is, to our knowledge, no reported data on their compatibility with the storage vessel and components in NG environment. High surface area porous materials such as Activated Carbons and Metal Organic Frameworks (MOF) are considered as the most promising adsorbents. The Cu3(btc)2 MOF, copper benzene-1,3,5-tricarboxylate also known as HKUST-1, has been extensively studied for gas storage. Herein we report its compatibility in NG environment with the pressure vessel, more particularly with the metal liner. We show that not only the stability of the adsorbent but also the integrity of the metallic liner can be drastically affected.
Evaluation of Candidate Materials for Use in Supercritical CO2 Environment
Authors: Rodriguez David , Karmiol Zachary , Summers Kodi , Chidambaram Dev 
Published: February 2020

Introduction

Supercritical CO2 is capable of being used in a variety of applications. These applications include; solvent for extraction, oil recovery, carbon capture and power generation (1-4). The areas of interest for this study will focus on conditions for advanced oil recovery and carbon capture and storage. The conditions of interest are above the critical point for CO2, which is 31.1°C and 7.39MPa (5).

Experimental

The autoclave contained CO2 at a pressure of 10 MPa and temperatures ranging from 40°C up to 150°C. Materials studied include; austenitic steels (stainless steel 304 and 316), and nickel based alloys (Inconel 625 and 718). Gamry software was used to control the potentiostat and analyze the data. Surface chemistry of the oxide layer was studied using X-ray diffraction, X-ray photoelectron and Raman spectroscopies.

Results

This study will discuss the corrosion current obtained and correlate it to the surface chemistry. Corrosion current was generally very low (e.g. 34.8nA for inconel 625 at 40°C).

Acknowledgements: This study was supported by the Department of Energy (DOE) under contract DE-NE0008236 and Nuclear Regulatory Commission (NRC) under awards NRC-38-10-949 and NRC-HQ-11-G-38-0039. D.R. is supported under a Fellowship program funded by NRC. Mr. Kenny Osborne and Ms. Nancy Hebron-Isreal serve as the program managers for the DOE and NRC awards, respectively.

References:

1. O. Babova, A. Occhipinti, A. Capuzzo and M. E. Maffei, The Journal of Supercritical Fluids, 107, 358 (2016).
2. L. Hu, D. Chen, Y. Huang, L. Li, Y. Cao, D. Yuan, J. Wang and L. Pan, Energy, 89, 874 (2015).
3. K. Li, X. Zhou, R. Tu, Q. Xie, J. Yi and X. Jiang, The Journal of Supercritical Fluids, 107, 298 (2016).
4. J. Beck, M. Fedkina, S. N. Lvov, M. E. Ziomek-Moroz, G. Holcomb, J. Tylczak and D. Alman, ECS Transactions, 45, 39 (2013).
5. S. W. Løvseth, G. Skaugen, H. G. J. Stang, J. P. Jakobsen, Ø. Wilhelmsen, R. Span and R. Wegge, Energy Procedia, 37, 7841 (2013).
Corrosion Suppression with Redox Control in KCl-MgCl2 Under Flow
Authors: Olson Luke Christopher , Gray Joshua R. , Martinez-Rodriguez Michael Joe , Fuentes Roderick Eliel , Garcia-Diaz Brenda Lee 
Published: February 2020

Solar power systems must be competitive with conventional energy sources in in terms of cost to make up a significant portion of the electric power grid. Solar power can likely more rapidly grow and make-up a larger portion of the US power grid if systems have energy storage capability that could continue to provide power for extended periods without sunlight and vary the power as needed (i.e. – be dispatchable). Concentrated solar power tower systems with thermal energy storage using advanced high operating temperature heat transfer fluids and advanced thermodynamic cycles can potentially meet the twin goals of low cost and high reliability while being dispatchable. Molten salts are a promising candidate for a high operating temperature heat transfer fluids. Due to the decomposition of molten nitrates at temperatures above about 550 °C, molten fluorides or chlorides are expected to be needed for higher temperature operation. KCl-MgCl2 is a promising heat transfer fluid due to its low cost and good thermal transport properties. Corrosion in molten chloride salts can be severe if salt chemistry is not well controlled. Research has shown that the main corrosion mechanism in Fe-Ni-Cr alloys exposed to molten salts is selective oxidation of Cr and that the corrosion mechanism is mass transfer limited. In the research to be presented, thermosiphons were operated at three different temperature ranges to add flow to corrosion tests and evaluate changed corrosion rates. Four alloys were tested in the thermosiphons with varying temperature and with and without Mg redox control. The most extreme case tested had the hot region at ~930 °C and cold region at ~880C. The research found that naturally convective flow could increase up to 5 times the corrosion compared to static tests for Haynes-230 without corrosion inhibition. Corrosion inhibition using Mg worked well to decrease corrosion and mass transfer reactions for Fe, Co, and Ni based superalloys.
(Invited) Development of in situ Electrochemical Small-Angle Neutron Scattering (eSANS) for Simultaneous Structure and Redox Characterization of Nanoparticles
Authors: Prabhu Vivek M , Reipa Vytas , Rondinone Adam J , Formo Eric , Bonnesen Peter V 
Published: February 2020

The demand for engineered nanomaterials in expanding research sectors, such as energy and healthcare, require materials with widely disparate physicochemical properties. The oxidation and reduction (redox) properties of nanomaterials are crucial for catalysis, matching semiconductor band gaps for photovoltaics, as well as toxicology, since they may cause oxidative stress by generating reactive-oxygen species. Optical spectroscopy analysis of molecular and nanomaterials undergoing redox reactions quantifies the electron transfer and energetics of the reaction via potential control and are the most common analytical techniques employed for this purpose. However, with conjugation to organic ligands and smaller, well-defined particle sizes, engineered nanomaterial redox characterization would benefit by techniques that provide nanometer sensitivity to nanoparticle core and ligand structure. We developed an in situ electrochemical small-angle neutron scattering (eSANS) method to measure simultaneously the redox properties and size, shape, and interactions of solution-dispersed nanomaterials [1]. By combining multi-step potentials and chronocoulometry readout with SANS, the structure and redox properties of engineered nanomaterials are followed, simultaneously in one experiment. Specifically, ZnO nanoparticles were examined as dilute dispersions in pH buffered deuterium oxide solutions under negative electrode potentials. The ZnO disk-shaped nanoparticles undergo an irreversible size transformation upon reduction at the vitreous carbon electrode. The decrease in average nanoparticle size near a current maximum shows the reduction reaction from ZnO to Zn occurs. The eSANS method provides nanometer scale sensitivity to the nanoparticle size and shape changes due to an electrochemical reaction that is crucial to understand in energy, healthcare, and other applications. These experiments utilized the EQ-SANS beamline at the Spallation Neutron Source, Oak Ridge National Laboratory that uniquely provides the ability to follow the redox kinetics under quasi-stationary potential step-scans. The methodology, contrast variation, and scattering properties of the micro and nanoporous carbon electrodes will also be described.
[1] V.M. Prabhu and V. Reipa, J. Phys. Chem. Lett. 3, 646 (2012)
(Invited) On the Modeling of the Charge Pumping Curves
Authors: Bauza Daniel 
Published: February 2020

The Charge Pumping (CP) technique has been used to characterize insulator semiconductor interface traps in numerous device types and in a wealth of situations [1]. A few years ago and for the first time, the three basic CP curves types recorded from conventional silicon MOSFETs with thick SiO2insulating films have been simulated very accurately in a large range of experimental conditions [2, 3], demonstrating that the model derived satisfactorily accounts for the CP mechanisms and that the properties of the traps introduced, i.e. their distribution and electrical characteristics, were plausible. As far as we know no more recent results have been published in that field. Indeed, one may expect the electrical CP response of gate stacks with high-k dielectrics to be even more difficult to tackle [1].
A part of the above results has been used more recently to investigate the meaning of CP curve edges [4]. This study pointed out the role that surface potential plays in interface traps filling and in CP curves shape. It was also shown that the Si-SiO2interface trap density, Dit, usually extracted as proposed in [5], can be very simply obtained from the slope of the CP curve edges [4].
Besides, a few months ago, several Pbo centers, the amphoteric defect well-known to be the main trap type at the Si(100)-SiO2 interface after SiO2 growth have been identified in deep submicron area MOSFETs [6], pursuing the story of the Si-SiO2interface electrical characterization.
In this paper, starting from the results presented in [2, 3], the essential of the model, the major advances with regard to previous work and the main conclusion that can be drawn concerning the CP mechanisms will be recalled. The impact of the gate signal parameters on carrier capture and emission will be detailed. The contributions to the overall CP signal of the different traps introduced along with the impact on the CP curve shape of their characteristics will be presented. The limitations of this approach will also be pointed out.
[1] Nanoscale CMOS – Innovative Materials, Modeling and Characterization, Ch. 15, Characterization of interface defects, by P. Hurley, O. Engström, D. Bauza, and G. Ghibaudo, Edited by F. Balestra, Ed. ISTE-Wiley 2010.
[2] D. Bauza, IEEE Trans. Electron Devices 56, 70, (2009).
[3] D. Bauza, IEEE Trans. Electron Devices 56, 78, (2009).
[4] D. Bauza, International Reliability Physics Symposium (IRPS) 2013, paper GD-2.
[5] G. Groeseneken, H.E. Maes, N. Beltran, and R. F. De Keersmaeker, IEEE Trans. Electron. Devices 31, 42 (1984).
[6] T. Tsuchyia and Y. Ono, Jap. J. Appl. Phys. 54, 04DC01 (2015).
Effects of Precursor Flow Rates on Characteristics of Low-K SiOC(H) Film Deposited by Plasma-Enhanced Chemical Vapor Deposition
Authors: Cheng Yi-Lung , Huang Chiao-Wei , Sun Chung-Ren , Lee Wen-Hsi 
Published: February 2020

In this study, low-dielectric constant (low-k) SiOC(H) films deposited using conventional plasma-enhanced chemical vapor deposition (PECVD) by varying flow rates of the deposition precursors were investigated through various characterization techniques. The deposition precursors were DEMS and ATRP, which acted as a network matrix and sacrificial porogen, respectively. Experimental results indicated that both DEMS and ATRT precursors influence the properties of resulting porous low-k SiOCH films. But matrix DEMS precursor causes greater impact. With an increase of DEMS flow rate, an enhanced cross-linking was formed, leading to a higher hardness, smaller pore size, better electric performance, and stronger dielectric breakdown strength. However, a higher dielectric constant (k) is the cost. The k values of the porous low-k SiOCH films with various ATRP flow rates (1700~2500 sccm) remained unchanged, although, the optimized electrical characteristics and reliability were obtained as ATRP flow rate was 2100 sccm.
Characterization of SiOx/HfOx Bilayer Resistive-Switching Memory Devices
Authors: Chen Ying-Chen , Chang Yao-Feng , Wu Xiaohan , Guo Meiqi , Fowler Burt , Zhou Fei , Pan Chih-Hung , Chang Ting-Chang , Lee Jack C. 
Published: February 2020

Oxide based resistive switching memory are the promising candidates for future non-volatile memory according to fast programing, low power operation, scalability and compatibility to the current CMOS process. Among, SiOx single layer resistive switching devices have been widely studied and characterized. The SiOx single layer resistive memory has good compatibility to CMOS fabrication process. However, it can only be programmed under the vacuum or non-oxidized ambient. Also, the previous results reported on SiOx-based memristors indicate that the electroforming and programming voltage is relatively higher than the other dielectric materials and obstructed for low-power applications. In this work, by using SiOx/HfOx stacking engineering, we have developed a low-voltage operation (< 2V) for SiOx-based ReRAM. The results show that with HfOx
(3nm) on bottom, the metal-insulator-semiconductor (MIS) structures exhibit resistive switching at low voltage (<2V) and operation in air atmosphere. The added hafnium layer apparently provides the source of proton exchange reaction with conduction bandgap offset reduction for low-voltage (< 2V) RS (Figure 2). Also, we have studied single HfOx-based MIS devices which exhibit bipolar-type resistive switching behaviors with small memory window.Clearly, SiOx/HfOx stacking optimization not only maintains the RS behaviors even in air environment without any programming window degradation, but also further reduces the switching voltage below 2V.
Figure 1 shows the results of three different structures, including SiOx single layer memristor, SiOx/HfOx bilayer memristor and HfOx single layer memristor. In terms of operation environment condition, inserting the HfOx layer would help the SiOx memristor to be able to programmed either under a pressure of 1E-4 torr or in the atmosphere. The HfOx single layer memristor has the lowest electroforming voltage of 2.3 V, and which in SiOx/HfOx stacks has been reduced significantly to 5 V comparing which of 14 V for SiOx single layer. For the SiOx/HfOx bilayer, a memory window of 4 decades is achieved and comparable to that of SiOx single layer, and larger than that of single layer HfOx by 2 decades. In terms of operation voltage, the set voltage is reduced from 4V to 2 V and the reset voltage is also suppressed significantly from 10 V to 0.3 V by inserting the 3 nm HfOx layer.
Figure 2 shows the TEM images of both SiOx single layer memristor and SiOx/HfOx bilayer memristor. The 3 nm HfOx was deposited on N+ Si wafer at 250 oC by atomic layer deposition followed by 30 nm SiO2 deposition using e-beam evaporator and 160 nm TaN depositing by sputtering.
Figure 3. The single layer HfOx-based MIS devices resistive switching behaviors. (a) The electroforming process, resistive switching behaviors in 20 times cycling. (b) The switching voltage (SET/RESET) and states (HRS/LRS) distribution.

Figure 1
(Invited) Quantification and Characterization of Adsorbed BTA on Copper Surfaces Under Conditions Relevant to Barrier CMP
Authors: Wu Bing , Raghavan Srini 
Published: February 2020

In the formation of copper interconnects by CMP, barrier polishing is typically carried out using alkaline slurries containing copper corrosion inhibitors. Benzotriazole (BTA) has been the inhibitor of choice in such slurries. The effect of BTA on copper corrosion has been extensively studied in the past few decades, and there is general agreement that the adsorbed film formed in acidic solutions is a multilayer film with a chemisorbed first layer. However, simultaneous real time measurement of the amount of BTA adsorbed and characterization of nature of the adsorbed film (rigid/viscoelastic) has received very little attention.
The objective of this work was to measure the extent of BTA adsorption onto PVD Cu films and characterize the nature of the adsorbed film in real time using a quartz crystal microbalance with dissipation monitoring (QCMD) capability. Quartz crystals (fundamental frequency of 5 MHz) coated with ~300 nm PVD copper layer were used in the experiments. To mimic the conditions during barrier polishing, BTA dissolved in alkaline solutions was pumped through the flow cell containing the crystal, and the change in crystal oscillation frequency and dissipation data were collected at a time resolution of fraction of a second for several minutes. This was followed by rinsing with DI or solutions containing selected surfactants to determine extent of desorption of BTA.
As an example, adsorption of BTA from a solution of pH 10 is shown in figure 1. The measured frequency shift (Δf) and dissipation shift (ΔD) at different overtones (multiples) of crystal fundamental frequency are plotted as a function of time. At the time marked with t1, a sharp decrease of frequency may be seen, which indicates rapid adsorption of BTA. The data points for all frequencies fall on one curve indicating that the adsorbed BTA film on copper is quite rigid in nature. This is confirmed by very little measured change in the ΔD values. At the end of adsorption marked with t2, deionized water was introduced into the system, and the positive shift of frequency is indicative of BTA removal and/or etching of copper in DI water.
In the presentation, results of adsorption and desorption experiments carried out under different experimental conditions will be presented. The disruption of adsorbed BTA layer by selected chemicals will be addressed.

Figure 1
The Mechanism of the Bridge Defect Caused By the Reaction with the Dispersant Polymer in Slurry and the Double Patterning Photo Layer
Authors: Kim Hyun-Soo , Jang Dong-Hyuk , Hwang Ha-Sub 
Published: February 2020

At the present time, semiconductor process technology node is going under 10nm from 20~30nm base. The 1X nm design rule will be general trend in the next few years. In this situation, the Chemical Mechanical Planarization (CMP) is focusing on the fine defect which is under 20nm. At this conference, I would present the mechanism of defect which caused by dispersant polymer, additive polymer and slurry inhibitor in ultimate fine design technology era. We found the medium weighted polymer chains were still remained after polishing even if in situ cleaning and ex-situ cleaning was performed. And the remained polymer reacted with the Photo Resistance (PR) material while processing double patterning (DPT). Since the defect size was so small, the defect was not detected in the processing. It is supposed that the compounds composed of slurry polymer and PR material block the etching reaction and make a bridge between line and line spacer. To prevent these polymer enhanced defects, well designed slurry should be used and the perfect cleaning solution is especially needed. The failure mechanism is that a lot of minus charged polymers attached on plus charged layer react with PR and DPT layer and finally going hardening on annealing around 200°C. So, the cleaning solution have to have higher polymer solubility to remove the additive polymer chains on minus or plus charged layer.
Molecular Characterization and Design of CMP Pads
Authors: Arnó Jose 
Published: February 2020

Together with slurries, pads play an important role in the mechanical and chemical processes used to polish and planarize wafers. Pads are typically characterized based on their bulk physical, mechanical, and microstructural properties as they correlate to polishing performance. Surface interactions at the pad-slurry interface can be characterized using contact angle and zeta potentiometry to measure surface energy and electrokinetic properties. The molecular structure of the polyurethane material is a critical factor that defines many of the aforementioned pad characteristics. For example, the stiffness of a chain and the degree of cross-linking are important factors in targeting hardness, elasticity, temperature resistance, and chemical affinity. The ability to measure and understand the polymer structure and bond composition of a pad is a critical tool to rationalize performance and to design new materials that address future polishing needs. In this paper, a fundamental molecular study on the polymer structure and network formation will be described. The work was performed using Fourier Transform infrared spectroscopy coupled with a thermally controlled attenuated total reflection (ATR) accessory. After an overview of the main polyurethane infrared absorption bands, the investigation will provide important molecular formation insights related to the polymerization reaction (gelation), curing, and final structure of the polymer.
Mechanical Properties of Functionally Graded Boron Carbide/Aluminum Cermets Utilizing Electrophoretic Deposition (EPD)
Authors: Morales Jason Rolando , Landingham Richard , Pascall Andrew J. , Worsley Marcus A. , Kuntz Joshua D. 
Published: February 2020

Gradient and laminate materials are an emerging area with the potential to impact a wide range of technologies including structural materials, energy storage, and defense applications. However, fine control of gradients is a challenge for many material types. This work aims to demonstrate the capability to tune the properties of ceramic-metal composites (cermets) by using electrophoretic deposition (EPD) to create compositional/microstructural gradients within the cermet part. Controlling the outcome of microstructural features and phase composition enables the tailoring of the final product for desired applications. B4C green body compacts comprised of tailored microstructures through EPD are then infused with Al during pressureless sintering.