Materials Science and Engineering Commons^™

The Study On Un-Doped/Boron Doped/Un-Doped Triple Seg In Vertical Nand Flash Memory, Woong Lee, Chaeho Kim, Joonsuk Lee, Sehun Park, Yonghan Roh

Journal of Metals, Materials and Minerals

Selective epitaxial growth (SEG) plays a critical role in vertical NAND flash memory because it serves as a ground select line (GSL) transistor, which is used to control the cell current in the vertical channel. In this study, different channel hole sizes between the adjacent hole and away hole from the common source line (CSL) were detected after vertical channel etch (VCE). This discrepancy severely impacts the boron concentration of SEG applied through ex-situ boron implantation, and results in large GSL Vth variations. Novel in-situ boron-doping of triple-layered un-doped/boron doped/un-doped SEG was developed to solve the high variation of the …

Oxidation Behavior Of Sn-1 Wt% Bi Alloy In Air And Deionized Water At Room Temperature, Tanavut Naravuthichai, Patama Visuttipitukul, Sirichai Leelachao, Tachai Luangvaranunt

Journal of Metals, Materials and Minerals

Formation of tin oxides on surface Sn-1 wt% Bi alloy lapping plates causes interactions with protrusions of embedded diamond grits, and reduces the efficiency of the lapping process. The rate and type of oxide formation were investigated to understand the problem. Electrochemical analysis was performed to characterize the oxide film thickness, and x-ray photoelectron spectroscopy was performed to characterize the tin oxide species. Oxidation in air at room temperature reaches a thickness of 23 Å after 72 h. Oxidation in deionized water at room temperature has a faster growth rate, and reaches a thickness of 33 Å after 72 h. …

Microwave-Assisted Ecofriendly Silver Nanoparticle Synthesis By Varieties Of Chrysanthemum Morifolium Ramat: Assessing Their Antioxidant, Photocatalytic And Antibacterial Activities, Mathivathani Kandiah, Laknee Nawamali De Silva

Journal of Metals, Materials and Minerals

Based on recent developments in the field of Nanobiotechnology, this study is aimed at the assessment of antioxidant, photocatalytic and antibacterial activities of silver nanoparticles (AgNPs) synthesized using Chrysanthemum morifolium Ramat varieties (brown, yellow, purple, pink, salmon pink and white), where five varieties produced AgNPs except white. Antioxidant assays such as total flavonoid content, total phenolic content and total antioxidant capacity and free radical scavenging assays such as ferric reducing antioxidant power and DPPH radical scavenging assays were performed. Photocatalytic activity was assessed by the degradation of the model dye methylene blue. Anti-bacterial activity was determined on Staphylococcus aureus and …

Structural, Magnetic And Transport Properties Of Ca And Sr Doped Lanthanum Manganites, Sunita Keshri, Shailendra Rajput, Sonali Biswas, Leena Joshi, Wojciech Suski, Piotr Wiśniewski

Journal of Metals, Materials and Minerals

This article presents a comparative study for the effect of average A-site cation size on the structural, transport and magnetic properties of Lanthanum manganites. Three polycrystalline colossal magneto-resistive compounds were synthesized using standard solid state reaction method. The electrical resistivity data were analyzed employing standard two-phase model to understand the conduction mechanism. The resistance of polycrystalline ceramic depends on the intragrain resistance (intrinsic resistance) and the intergrain or grain-boundary resistance (extrinsic resistance). The substitution of Sr ions at La-site provides higher magnetic and metal-insulator transitions as compared to Ca ions. The combined substitution of Ca and Sr ions at La-site …

Formation Of Nano-Crystalline Chromium-Zirconium Nitride (Cr-Zr-N) Film Coating By Dc Unbalanced Magnetron Sputtering, Kumpon Leelaruedee, Kattareeya Taweesup, Patama Visuttipitukul

Journal of Metals, Materials and Minerals

This research aimed to improve the properties of chromium nitride (CrN) film coatings by addition of zirconium (Zr) as the third element to form Cr-Zr-N ternary nitride. DC unbalanced magnetron sputtering method was used to form Cr-Zr-N film with various Zr/Zr + Cr atomic ratios.  Mechanical properties, surface morphology and crystal structure of the film were investigated. In the research, Cr-Zr-N film were categorised into 3 types with different Zr amount: low zirconium, (Zr/Zr + Cr = 0.29), medium zirconium (Zr/Zr + Cr = 0.44), and high zirconium (Zr/Zr + Cr = 0.74). All Cr-Zr-N films exhibited nano-crystalline structures with …

Improvement Of The Superconducting Properties Of Carbon Addition On Bi1.6pb0.4sr2 Ca2cu3o10+Δ Prepared Through The Two-Step Sintering Process, Dini Rizqi Dwikunti Siregar, Sigit Dwi Yudanto, Septian Adi Chandra, Eka Feby Ronauli Lubis, Syahrul Humaidi, Nono Darsono

Journal of Metals, Materials and Minerals

The effects of the addition of carbon nanoparticles and nanotubes on the Bi1.6Pb0.4Sr2Ca2Cu3O10+δ (BPSCCO) have been reported. BPSCCO samples were synthesized using the sol-gel method. BPSCCO with nominal composition was sintered at 840°C for 30 h, then grounded and added an amount of carbon. Pure and carbon added BPSCCO were sintered at 840°C for 30 hours. Resistivity measurements were carried out to determine the superconducting properties of the samples. We found that the addition of carbon nanoparticles and nanotubes increased the critical zero temperature (Tc-zero) of BPSCCO from 94.67 K to 97.8 K and 102.03 K for the pure BPSCCO, …

Mechanical Performance Of Woven Carbon Reinforced Epoxy Composites With Varied Orientation Angle, Sweety Ashish Agrawal, Someshwar Bhattacharya

Journal of Metals, Materials and Minerals

The mechanical properties of woven carbon fibre reinforced epoxy composites laminated with different orientation angle in stacking sequence were investigated. Woven fabric layers with different linear density carbon tow have been produced on modified rigid rapier sample loom and impregnated with epoxy by hand lay-up technique for composite preparation. Curing of composite was carried out at room temperature for 2 h. Five different laminar composites were prepared with different orientation angles [(0/0/0/0), 0/+30/-30/0, 0/+45/-45/0, 0/+60/-60/0 and 0/+90/-90/0]. The mechanical properties like tensile, flexural, and impact test) were analysed in both longitudinal and transverse directions. Physical properties such as density and …

Investigation Of Optimum Parameters For Rotary Friction Welding Of Aluminum Round Bars Using Three-Level Factorial Design Methodology, Tanakorn Jantarasricha, Siridech Kunhirunbawon, Montri Wimol

Journal of Metals, Materials and Minerals

The welding process has been essential to increasing productivity in numerous industries across Thailand. There are several welding processes to choose from, and the welding process to use will be determined by the suitability of the production in that industry. Another important consideration in welding is to keep the mechanical properties of the joint area as close to the parent material workpiece as possible. This research aims to select the optimum parameter for rotary friction welding aluminum round bar AA6063-T5. That is according to the DIN 50125 type B standard test. The optimal condition consists of welding rotational speed, welding …

Controlled Plasma Tuning Of Mos2 Based Photodetector: From Visible To Ultraviolet Photo Response, Huda Musa Mutlaq, Ali Jabbar Fraih

Journal of Metals, Materials and Minerals

Among diverse family of two-dimensional materials, molybdenum disulfide (MoS2) is one of the most promising materials for optical applications thanks to its tunable optical energy bandgap. In this work, a MoS2 based photodetector is fabricated and its optical properties is investigated. With the help of controlled oxygen plasma bombardment, its photoresponse is tuned from visible to ultraviolet region. The photodetector was subjected to three bombardment times of 60 s, 120 s, and 180 s, and it was observed that 180 s irradiation resulted in a change in the optical response range of the photodetector from visible to ultraviolet. In fact, …

Stress Softening Characteristics Of Thin Monoholar Rubber Flat Slab, Kulyuth Boonseng, Chatchai Waiyapattanakorn, Prayoon Surin

Journal of Metals, Materials and Minerals

Thin monoholar rubber flat slab gives rise to unconventional mechanical properties under tension loading not found in thin solid rubber flat slab. However there has been no proper report on its stress softening characteristics. Stress softening is an important phenomenon occurring in all elastomeric materials under cyclic tension loading. Parameters pertinent to stress softening investigated in this research are stress-strain characteristics, permanent set strain and hysteresis loss energy of the thin monoholar rubber flat slab in comparison with the thin solid rubber fat slab when undergoing 7 cycles of stretching. Noticeable differences of stress-strain hysteresis loops diminution of the thin …

Synthesis And Optical Properties Of Forsterite Ceramic Pigments Using Mirror Wastes As A Flux, Niti Yongvanich, Natchaya Lithira, Nitchakarn Nuniead, Wanchalerm Chauyarsa

Journal of Metals, Materials and Minerals

Cobalt-doped forsterite ceramic pigments based on the formula (Mg2-2xCo2x)SiO4 (x = 0, 0.05, 0.1, 0.2) were synthesized using mirror wastes as a flux. Addition of this flux enhanced forsterite phase formation at lower temperature by as much as 200℃. The resulting pigment particles were in a micron range which is suitable for use in a ceramic glaze. The host structure (Mg2SiO4) could accommodate cobalt cations up to 20 at%. Investigation on the chemical distribution revealed that no chemical species from the flux reacted with pigment grains. Optical properties were examined by UV-vis spectroscopy and colorimetry. Technical performance of the obtained …

Retaining The High-Temperature Phases Of Rb3h(So4)2 And Rb5h3(So4)4 At Room Temperature, Chatr Panithipongwut Kowalski

Journal of Metals, Materials and Minerals

The attempts to maintain the higher-temperature phases of Rb3H(SO4)2 and Rb5H3(SO4)4 were demonstrated in this work for the first time. The goal was to explore the possibility to utilize solid acids at lower temperatures while keeping the high-temperature phases which connects to the desirable conductivities. Enabling to do so will allow the ease of handling and thermal cycling, and the energy saving in fuel cell applications, and will allow researchers to study the high-temperature properties of solid acids at lower temperatures without the expenses for the in-situ measurements and the accessibility limitations. The four relatively simple methods, which were the …

Poly(Vinyl)Alcohol Film Composited With Carbon Dots From Water Hyacinth Stalks Based On Gamma Irradiation For The Uv Blocking Film, Tanagorn Kwamman, Threeraphat Chutimasakul, Panida Sangangam, Nattamon Puengposop, Kanokorn Wechakorn

Journal of Metals, Materials and Minerals

UV-radiation in the range of 200 nm to 400 nm from sunlight can inhibit the photosynthesis process in plants, while visible light in the range of 400 nm to 700 nm promotes photosynthesis and plant growth. In this work, poly(vinyl)alcohol-carbon dots composite film (PVA-CDs film) was developed as a UV-blocking film due to the excellent optical properties of carbon dots and the film-forming properties of PVA. For the synthesis of carbon dots using gamma irradiation, water hyacinth stalk, an invasive aquatic plant, was used as a carbon source. The result showed that PVA-CDs composite film exhibited excellent UV absorption (200 …

Photoelectrochemical Cathodic Protection Of Amorphous Zinc Oxide Coating On Hot Rolled Steel Ss400 In A 3 Wt% Nacl Solution And A Na2s-Naoh Solution, Phatchara Wipataphan, Worapot Sripianem, Naw Blessing Oo, Thanate Na Wichean, Boossayamas Dachbumroong, Oratai Jongprateep, Gasidit Panomsuwan, Naray Pewnim, Ratchatee Techapiesancharoenkij

Journal of Metals, Materials and Minerals

The photoelectrochemical cathodic protection of amorphous ZnO thin-film coating on hot rolled steel SS400, in the 3 wt% NaCl environment, was investigated. The ZnO thin film was coated on a SS400 substrate at 200℃ using the spray pyrolysis technique. The x-ray diffractometry analysis confirmed the amorphous ZnO coatings. Two different types of the electrochemical cells were used: a single-cell and a double-cell system. Two different types of the photoelectrolytic solutions were compared: (i) 0.1 M Na2S + 0.2 M NaOH and (ii) 3 wt% NaCl solution. The ZnO-coated SS400 samples were subjected to potentiostatic polarization testing under dark and UV …

Influence Of Graphite Feedstock On The Characteristics Of Silver-Decorated Graphene Oxide And Antimicrobial Property, Ebrahim Mahmoudi, Wei Lun Ang, Gasidit Panomsuwan, Oratai Jongprateep, Abdul Wahab Mohammad, Law Yong Ng, Muneer M. Ba-Abbad

Journal of Metals, Materials and Minerals

Graphite from different sources has significant influence on the properties of graphene oxide (GO) and reactivity of GO towards further modification with other nanoparticles. However, such effect has not yet been properly explored. This study aims to investigate the characteristics and antimicrobial property of GO decorated with silver nanoparticles (known as Ag-GO composite) where the GO is synthesized via modified Hummer’s method from various graphite feedstock, namely natural graphite flake (NGF), natural graphite powder (NGP), and synthetic graphite powder (SGP). The Ag-GO nanocomposite was then synthesized using chemical reduction methods. Antimicrobial properties of the Ag-GO were tested using the standard …

Luminescent Properties Of Polyaniline Capped Mn Doped Zns Quantum Dots, Anju Bala, Rajeev Sehrawat, Anil Kumar Sharma, Pardeep Soni

Journal of Metals, Materials and Minerals

Synthesis of polyaniline capped and Mn doped quantum dots are performed with co-precipitation tech. while structural, optical and morphological properties have been carried out by using Fourier Transform Infrared Spectroscopy (FTIR), X-Ray Diffraction (XRD) study, photoluminescent (PL), absorption spectroscopy and High-Resolution Transmission Electron Microscopy (HR-TEM). Particles size is nearly 2 nm calculated using XRD analysis and nearly 2.5 nm as estimated from HR-TEM study. FTIR spectra confirm that ZnS and polyaniline interact through S-H vibrations. The absorption spectra analysis reflects the occurrence of blue shift at the peak of absorption along with the enhanced band gap of polyaniline capped ZnS(Mn) …

Analysis Of Post-Deposition Recrystallization Processing Via Indium Bromide Of Cu(In,Ga)Se2 Thin Films, Deewakar Poudel, Benjamin Belfore, Tasnuva Ashrafee, Shankar Karki, Grace Rajan, Angus Rockett, Sylvain Marsillac

Applied Research Center Publications

Cu(In,Ga)Se₂ (CIGS) thin films were deposited at low temperature (350 °C) and high rate (10 µm/h) by a single stage process. The effect of post-deposition treatments at 400 °C and 500 °C by indium bromide vapor were studied and compared to the effect of a simple annealing under selenium. Structural, electrical, and chemical analyses demonstrate that there is a drastic difference between the different types of annealing, with the ones under indium bromide leading to much larger grains and higher conductivity. These properties are associated with a modification of the elemental profiles, specifically for gallium and sodium.

Continuous Preparation And Application Of Novel Heterogeneous Catalysis, Michael B. Burkholder

Theses and Dissertations

Transition metal heterogeneous catalysts are widely used across many chemical industries to reduce waste and emissions and reduce production time while increasing rate. The prevalence of these materials results from the complex relationship between metal nanoparticles and supports affecting final catalytic performance. Rational catalyst synthesis describes the ability to precisely engineer structures through controlled preparation. Novel materials and continuous processing represent a promising approach for rational catalyst synthesis.

The application of these catalysts in continuous, multiphase processes, such as cross-coupling reactions, oxidation chemistry, and nitroreduction processes, are paramount to developing new commercial routes for high-value products. Pd/G catalysts synthesized by …

Surface Characterization Of Accident Tolerant Fuel Claddings Candidates After Prolonged Exposure To Steam Oxidation, Connor F. Donlan

Theses and Dissertations

Accident Tolerant Fuel Claddings are designed to improve fuel performance and safety in abnormal reactor conditions. The development of these cladding materials has become a top priority for the nuclear community, with incidents such as the Three Mile Island accident and the Fukashima Dai-chi accident. The development of these claddings has resulted in 2 subsections: coating current claddings or replacing cladding materials with new materials. The claddings studied in this thesis are a Zircaloy-4 cladding coated with chromium through physical vapor deposition, Zircaloy-4, and a FeCrAl alloy, C26M. This thesis assessed the surface chemistry, roughness, and wettability after extended exposure …

Biomass-Derived Electrode Materials And Sustainable Processes For Supercapacitors, Katelyn M. Shell

Theses and Dissertations

Biomass is one of the most abundant natural resources and has been used as a source of energy for thousands of years. Biomass as a precursor for energy storage materials is still relatively novel and faces several obstacles before becoming commonly used in today’s electrical devices. Currently, energy storage devices, such as batteries, capacitors, and supercapacitors, utilize petroleum-derived graphitic carbons for anodes, generating a need for more sustainable materials. Biomass, as a carbon-rich source for electrode materials, presents a viable and economically feasible alternative due to the prevalent lignocellulosic compounds: lignin, cellulose, and hemicellulose. Preliminary studies on the solid residues …

Perovskite Thin Films Annealed In Supercritical Fluids For Efficient Solar Cells, Gilbert Annohene

Theses and Dissertations

In the field of photovoltaics, scientists and researchers are working fervently to produce a combination of efficient, stable, low cost and scalable devices. Methylammonium lead trihalide perovskite has attracted intense interest due to its high photovoltaic performance, low cost, and ease of manufacture. Their high absorption coefficient, tunable bandgap, low-temperature processing, and abundant elemental constituent provide innumerable advantages over other thin film absorber materials. Since the perovskite film is the most important in the device, morphology, crystallization, compositional and interface engineering have been explored to boost its performance and stability. High temperatures necessary for crystallization of organic-inorganic hybrid perovskite films …

Accident Tolerant Fuels Claddings And The Evolution Of Their Surface Characteristics Under Critical Heat Flux, Rajnikant V. Umretiya

Theses and Dissertations

Enhanced Accident Tolerant Fuels (ATFs) systems for light water reactors require higher temperature oxidation resistance in steam environments than the current UO₂ – zirconium fuel system. Investigating the ATF materials’ surface properties is needed as they have evidenced to affect the Critical Heat Flux (CHF), which is an important parameter of the thermal-hydraulic performance required to provide safety margins. In this dissertation, the surface properties of FeCrAl alloys (APMT and C26M), Zircaloy-2, Zircaloy-4, and Cr-coating on Zircaloy-4 substrates produced by Physical Vapor Deposition (PVD) and Cold Spray (CS) were investigated according to their chemistry, topography, and wettability. The static …

Equations Of State For Warm Dense Carbon From Quantum Espresso, Derek J. Schauss

Theses and Dissertations

Warm dense plasma is the matter that exists, roughly, in the range of 10,000 to 10,000,000 Kelvin and has solid-like densities, typically between 0.1 and 10 grams per centimeter. Warm dense fluids like hydrogen, helium, and carbon are believed to make up the interiors of many planets, white dwarfs, and other stars in our universe. The existence of warm dense matter (WDM) on Earth, however, is very rare, as it can only be created with high-energy sources like a nuclear explosion. In such an event, theoretical and computational models that accurately predict the response of certain materials are thus very …

Impact Dynamics Of Surfactant-Laden Droplets On Non-Wettable Coatings, Amir Esmaeili

Theses and Dissertations

Owing to their excellent water repellency, non-wettable (superhydrophobic) coatings have gained tremendous attention in the past couple of decades. Alkyl ketene dimer (AKD), an inexpensive polymer frequently used in paper industry as a sizing agent, has shown potentials to become superhydrophobic. The formation of a porous structure after curing the solidified AKD for an extra-long time (4–6 days) results in superhydrophobicity, i.e., a static contact angle with water of >150° and a roll-off angle of <10°. In this work, a facile and low-cost method was used to turn the surface of AKD superhydrophobic in a very short period of time by briefly treating the coatings, obtained from isothermally heated molten AKD at 40 °C for 3 min, with ethanol. The resulting superhydrophobicity is due to the formation of porous, entangled irregular micro/nano textures that create air cushions on the surface leading to droplet state transition from Wenzel to Cassie. As a proof of concept, the same material was applied to the co-sputtered nickel-tungsten thin films, commonly used in micro/nano-electro-mechanical systems, to improve their hydrophobicity. According to the results, at least 20% increase was observed in the dynamic contact angles of the treated substrates.

In addition, this work presents a detailed high-speed imaging analysis of the influence of the molecular weight, concentration and ionic nature of surfactants on droplet …

Determination Of Hydrogel Degradation By Passive Mechanical Testing, Avery Rosh-Gorsky

Honors Theses

This paper details a new technique to measure the mechanical properties of ETTMP PEGDA hydrogels using Hertz Contact Theory and simultaneously analyze both the model drug release and gel erosion in situ. This method involves curing a drug loaded hydrogel in a standard cuvette and placing a glass bead and phosphate buffer solution (PBS). Over time, the cross-linked network of the hydrogel breaks down, and, as a result, the ball sinks into the hydrogel. This method provides a macroscopic and inexpensive way to continuously and passively measure properties of the hydrogel as the hydrogel degrades. By plotting both the …

Incorporation Of Perlite And Recycled Aggregates For Internal Concrete Curing, Yosra El Maghraby, Mohamed Nagib Abou-Zeid Prof., Mohamed Abdel-Raouf Dr.

Civil Engineering

No abstract provided.

Potential Advantages Of Basalt Frp Bars Compared To Carbon Frp Bars & Conventional Steel, Yosra El Maghraby, Mohamed Nagib Abou-Zeid Prof., Ezzeldeen Yazeed El Sayed Ahmed Prof

Civil Engineering

No abstract provided.

Viability Of A Proposed Transparent Fluid Model For Analog Metal Casting Filling Process, Andres Segura Irazoqui

Dissertations and Theses @ UNI

This research work was conducted to develop a proposed transparent fluid model to mimic dross formation and dispersion in metal castings during the mold filling process. The major cause for dross formation includes the air entrainment, surface turbulence, and bubbles, which create oxide films inside the molten metal. The oxide films are trapped inside the casting after solidification causing detrimental effects on the mechanical properties of the casting.

The objective of the investigation was to explore the feasibility using phenolic urethane as a transparent fluid material to investigate air entrainment mechanism. The experimentation consists of the following materials: the phenolic …

Degradation Issues And Stabilization Strategies Of Protonic Ceramic Electrolysis Cells For Steam Electrolysis, Hanrui Su, Yun Hang Hu

Michigan Tech Publications, Part 1

Protonic ceramic electrolysis cells (PCECs) are attractive electrochemical devices for converting electrical energy to chemicals due to their high conversion efficiency, favorable thermodynamics, fast kinetics, and inexpensive materials. Compared with conventional oxygen ion-conducting solid oxide electrolysis cells, PCECs operate at a lower operating temperature and a favorable operation mode, thus expecting high durability. However, the degradation of PCECs is still significant, hampering their development. In this review, the typical degradations of PCECs are summarized, with emphasis on the chemical stability of the electrolytes and the air electrode materials. Moreover, the degradation mechanism and influencing factors are assessed deeply. Finally, the …

Mechanical Activation And Cation Site Disorder Of Spinel-Based Ceramics, Cole A. Corlett

Masters Theses

"This research focuses on the processing and the effects that has on the cation disorder of magnesium-aluminate spinel based (MgAl₂O₄) ceramics. The first goal of this project was to determine the effects of high-energy milling, i.e., mechanical activation, on cation disorder (inversion) within the spinel structure. First, 1:1 molar ratios of MgO:Al₂O₃ ceramics were processed using two green processing methods, ball milling (XD) and SPEX milling (mechanical activation, MA) followed by a subsequent annealing treatment in air to form a single spinel phase in each powder sample. Neutron diffraction analysis was employed to …