Correlation between Powder Characteristic and Microstructure Development of Y-Doped BaCeO3

2014 ◽  
Vol 90 ◽  
pp. 78-83
Author(s):  
H.E. Araujo ◽  
D.P.F. Souza
Keyword(s):  
Diffusion Coefficient ◽  
Fracture Surface ◽  
Grain Growth ◽  
Sem Analysis ◽  
Microstructure Development ◽  
X Ray ◽  
Calcination Step ◽  
Citrate Process

Ceramics based on Y-doped BaCeO3 were prepared by citrate process. The X-ray fluorescence shows that barium stoichiometry deviation is established during calcination step. Through the SEM analysis of fracture surface of sintered samples it was possible to infer that powder highly deficient of barium shows higher diffusion coefficient during sintering than stoichiometric powder promoting grain growth and, consequently, trapping pores into the grains.

Synthesis of Ag-Hydroxyapatite

2016 ◽  
Vol 720 ◽  
pp. 234-238
Author(s):  
Flavia Mendonça Fonseca ◽  
Andrea Machado Costa ◽  
Rubens Lincoln Santana Blazutti Marçal ◽  
Daniel Navarro da Rocha ◽  
José Brant de Campos ◽  
...  
Keyword(s):  
Fourier Transform ◽  
Ftir Spectroscopy ◽  
Grain Growth ◽  
Sem Analysis ◽  
Precipitation Method ◽  
X Ray Diffraction ◽  
Spectroscopy Analysis ◽  
X Ray ◽  
Heat Treated ◽  
Xrd Patterns

Silver-bioceramics have a great potential to optimize the bone grafts materials to avoid microorganism infections on patients. The present study synthesized and characterized hydroxyapatite doped with silver (Ag), by an acidic route of precipitation method, and the proposal of the Ag-HA synthesis is to promote the bioactivity and bactericidal ability with less toxicity for organism. The samples were analyzed by X-ray diffraction (XRD) and Fourier transform infrared (FTIR) spectroscopy analysis. There was a pronounced grain growth after 1100°C HA and AgHA heat treatments for both HA and Ag-HA powders, observed by FEG-SEM analysis. XRD patterns of AgHA sintered at 1100°C showed HA as the main phase, but also a secondary whitlockite phase. However, 100% HA was observed for the Ag-HA samples heat treated at 700°C and 900°C. However, pure HA showed decomposition at 900°C. The acidic route of precipitation method showed to be effective for silver-doped hydroxyapatite production.

scholarly journals Incorporation of silver stearate nanoparticles in methacrylate polymeric monoliths for hemeprotein isolation

2020 ◽  
Vol 18 (1) ◽  
pp. 399-411
Author(s):  
Eman Alzahrani
Keyword(s):  
Noble Metals ◽  
Extraction Process ◽  
Sem Analysis ◽  
X Ray ◽  
Polymeric Scaffold ◽  
Extended Surface ◽  
Unique Method ◽  
Unique Approach ◽  
Ft Ir ◽  
Ft Ir Spectroscopy

AbstractA unique method was used to synthesize extremely stable silver stearate nanoparticles (AgStNPs) incorporated in an organic-based monolith. The facile strategy was then used to selectively isolate hemeproteins, myoglobin (Myo) and hemoglobin (Hb). Ethyl alcohol, silver nitrate, and stearic acid were, respectively, utilized as reducing agents, silver precursors, and capping agents. The color changed to cloudy from transparent, indicating that AgStNPs had been formed. AgStNP nanostructures were then distinctly integrated into the natural polymeric scaffold. To characterize the AgStNP–methacrylate polymeric monolith and the silver nanoparticles, energy-dispersive X-ray (EDX), scanning electron microscopy (SEM), and Fourier-transform infrared (FT-IR) spectroscopy were used. The results of the SEM analysis indicated that the AgStNP–methacrylate polymeric monolith’s texture was so rough in comparison with that of the methacrylate polymeric monolith, indicating that the extraction process of the monolith materials would be more efficient because of the extended surface area of the absorbent. The comparison between the FT-IR spectra of AgStNPs, the bare organic monolith, and AgStNP–methacrylate polymeric monolith confirms that the AgStNPs were immobilized on the surface of the organic monolith. The EDX profile of the built materials indicated an advanced peak of the Ag sequence which represented an Ag atom of 3.27%. The results therefore established that the AgStNPs had been successfully integrated into the monolithic materials. Extraction efficiencies of 92% and 97% were used to, respectively, recover preconcentrated Myo and Hb. An uncomplicated method is a unique approach of both fabrication and utilization of the nanosorbent to selectively isolate hemeproteins. The process can further be implemented by using other noble metals.

scholarly journals Grain Growth and Coarsening Dynamics in a Compositionally Asymmetric Block Copolymer Revealed by X-ray Photon Correlation Spectroscopy

2020 ◽  
Vol 53 (19) ◽  
pp. 8233-8243
Author(s):  
Ronald M. Lewis ◽  
Grayson L. Jackson ◽  
Michael J. Maher ◽  
Kyungtae Kim ◽  
Suresh Narayanan ◽  
...  
Keyword(s):  
Block Copolymer ◽  
Grain Growth ◽  
Photon Correlation Spectroscopy ◽  
Correlation Spectroscopy ◽  
Photon Correlation ◽  
X Ray ◽  
Coarsening Dynamics

Preparation and Characterisation of TiO2 Thick Films Fabricated by Electrophoretic Deposition

2007 ◽  
Vol 561-565 ◽  
pp. 2163-2166 ◽  
Author(s):  
H.Z. Abdullah ◽  
Charles C. Sorrell
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Grain Growth ◽  
Electrophoretic Deposition ◽  
Defect Formation ◽  
Titanium Foil ◽  
X Ray Diffraction ◽  
Voltage Range ◽  
X Ray ◽  
Scanning Electron

Rutile nano-powders were suspended in a solution of acetylacetone and iodine. The suspensions were electrophoretically deposited on titanium foil at a voltage range of 5-30 V over times of 5-120 s. The dried tapes then were sintered at 800°C for 2 h in flowing argon. Both the green and fired tapes were examined by field emission scanning electron microscopy, optical microscopy, X-ray diffraction, and Raman microspectroscopy. The thickness of the films depended on the voltage and the time of deposition. The sintered microstructures depended significantly on the thickness of the film, which was a function the proximity to the Ti/TiO2 interface. The interface is critical to the microstructure because it acts as the source of defect formation, which enhances sintering, grain growth, and grain facetting.

Microstructure Evolution of a Fine Grain Al-50wt%Si Alloy Fabricated by High Energy Milling

2011 ◽  
Vol 479 ◽  
pp. 54-61 ◽  
Author(s):  
Fei Wang ◽  
Ya Ping Wang
Keyword(s):  
Grain Growth ◽  
Microstructure Evolution ◽  
Room Temperature ◽  
Milling Time ◽  
High Energy ◽  
X Ray Diffraction ◽  
Scanning Calorimetry ◽  
Laser Method ◽  
X Ray ◽  
Fine Grain

Microstructure evolution of high energy milled Al-50wt%Si alloy during heat treatment at different temperature was studied. Scanning electron microscope (SEM) and X-ray diffraction (XRD) results show that the size of the alloy powders decreased with increasing milling time. The observable coarsening of Si particles was not seen below 730°C in the high energy milled alloy, whereas, for the alloy prepared by mixed Al and Si powders, the grain growth occurred at 660°C. The activation energy for the grain growth of Si particles in the high energy milled alloy was determined as about 244 kJ/mol by the differential scanning calorimetry (DSC) data analysis. The size of Si particles in the hot pressed Al-50wt%Si alloy prepared by high energy milled powders was 5-30 m at 700°C, which was significantly reduced compared to that of the original Si powders. Thermal diffusivity of the hot pressed Al-50wt%Si alloy was 55 mm2/s at room temperature which was obtained by laser method.

Development of Ternary Concrete Utilizing Agricultural Waste Material

2022 ◽  
Author(s):  
Sunita Kumari ◽  
Dhirendra Singhal ◽  
Rinku Walia ◽  
Ajay Rathee
Keyword(s):  
Rice Husk ◽  
Rice Husk Ash ◽  
Agricultural Waste ◽  
Xrd Analysis ◽  
Sem Analysis ◽  
X Ray Diffraction ◽  
X Ray ◽  
Concrete Mix ◽  
Maize Cob

Abstract The present project proposes to utilize rice husk and maize cob husk ash in the cement to mitigate the adverse impact of cement on environment and to enhance the disposal of waste in a sustainable manner. Ternary concrete / MR concrete was prepared by using rise husk and maize cob ash with cement. For the present project, five concrete mixes MR-0 (Control mix), MR-1 (Rice husk ash 10% and MR-2.5%), MR-2 (Rice husk ash 10% and MR-5%), MR-3 (Rice husk ash 10% and MR-2.5%), MR-4 (Rice husk ash 10% and MR-2.5%) were prepared. M35 concrete mix was designed as per IS 10262:2009 for low slump values 0-25mm. The purpose is to find the optimum replacement level of cement in M35 grade ternary concrete for I – Shaped paver blocks.In order to study the effects of these additions, micro-structural and structural properties test of concretes have been conducted. The crystalline properties of control mix and modified concrete are analyzed by Fourier Transform Infrared Spectroscope (FTIR), Scanning Electron Microscopy (SEM), and X-Ray Diffraction (XRD). The results indicated that 10% Rice husk ash and 5% maize cob ash replaced with cement produce a desirable quality of ternary concrete mix having good compressive strength. The results of SEM analysis indicated that the morphology of both concrete were different, showing porous structure at 7 days age and become unsymmetrical with the addition of ashes. After 28 day age, the control mix contained more quantity of ettringite and became denser than ternary concrete. XRD analysis revealed the presence of portlandite in large quantity in controlled mix concrete while MR concrete had the partially hydrated particle of alite.

A Mechanism of Polycrystallization in Fully Lamellar Ti-48Al-8Nb Single Crystal Alloy Aged at Elevated Temperatures

2002 ◽  
Vol 753 ◽  
Author(s):  
Yukinori Yamamoto ◽  
Masao Takeyama ◽  
Takashi Matsuo
Keyword(s):  
Growth Rate ◽  
Diffusion Coefficient ◽  
Single Crystal ◽  
Grain Growth ◽  
Elevated Temperatures ◽  
Volume Diffusion ◽  
Activation Enthalpy ◽  
Lamellar Microstructure ◽  
Aged Sample ◽  
Fully Lamellar

ABSTRACTPolycrystallization mechanism of a fully lamellar microstructure during aging at 1473 and 1273 K has been examined using Ti-48Al-8Nb fully lamellar single crystal, which consists mostly of γ/γ interfaces (variant, perfect-twin and pseudo-twin boundaries). After a certain period of aging, a few γ grains are formed within the lamellae and the lamellar microstructure collapses rapidly to become a γ grained microstructure at both temperatures. An EBSP analysis for aged sample revealed that most of the grains follow the orientation of variant domains in the lamellar microstructure. A kinetic analysis of the grain growth during aging revealed that the activation enthalpy of the growth rate is estimated to be 390 kJ/mol, which is very close to that for volume diffusion coefficient of Al and Nb in γ-TiAl. Based on the results, it is concluded that the formation of the grains is attributed to coarsening of variant domains within the lamellar plates and coalescence of the same variant domains across the lamellae, leading to a γ grained microstructure following the orientation of variant domains. These reactions also make the number of the variant domains decrease during aging, which remains only two variant domains with perfect-twin relationship.

Deposition of Cobalt Doped Zinc Oxide Thin Film Nano-Composites Via Pulsed Electron Beam Ablation

MRS Advances ◽  
2016 ◽  
Vol 1 (6) ◽  
pp. 433-439 ◽  
Author(s):  
Asghar Ali ◽  
Patrick Morrow ◽  
Redhouane Henda ◽  
Ragnar Fagerberg
Keyword(s):  
Zinc Oxide ◽  
Electron Beam ◽  
Binding Energy ◽  
Photoelectron Spectroscopy ◽  
Xrd Analysis ◽  
Sem Analysis ◽  
Oxide Thin Film ◽  
X Ray ◽  
Pulsed Electron Beam ◽  
Deposited Films

AbstractThis study reports on the preparation of cobalt doped zinc oxide (Co:ZnO) films via pulsed electron beam ablation (PEBA) from a single target containing 20 w% Co on sapphire (0001) and silicon (100) substrates. The films have been deposited at various temperatures (350оC, 400оC, 450оC) and pulse frequencies (2 Hz, 4 Hz), under a background argon (Ar) pressure of about 3 mtorr, and an accelerating voltage of 14 kV. The surface morphology has been examined by atomic force microscopy (AFM) and scanning electron microscopy (SEM). According to SEM analysis, the films consist of nano-globules whose size is in the range of 80-178 nm. Energy dispersive x-ray spectroscopy (EDX) reveals that deposition is congruent and the prepared films contain ∼20±5 w% cobalt. It has been found that the nano-globules in the deposited films are cobalt-rich zones containing ∼70 w% Co. From x-ray photoelectron spectroscopy (XPS) analysis, Co 2p3/2 peaks indicate that the deposited films contain CoO (binding energy = 780.5 eV) as well as metallic Co (binding energy = 778.1-778.5 eV). X-ray diffraction (XRD) analysis supports the presence of metallic Co hcp phase (2ϴ = 44.47° and 47.43°) in the films.

Characterization of Mn0.67Zn0.33Fe2O4 Nanoparticles Synthesized under Different pH

2017 ◽  
Vol 899 ◽  
pp. 48-53
Author(s):  
Rodrigo Uchida Ichikawa ◽  
Walter Kenji Yoshito ◽  
Margarida Juri Saeki ◽  
Willian C.A. Maranhão ◽  
Fátima Goulart ◽  
...  
Keyword(s):  
Profile Analysis ◽  
Rietveld Method ◽  
Spinel Phase ◽  
Sem Analysis ◽  
Line Profile Analysis ◽  
X Ray ◽  
Cell Parameters ◽  
Zn Ferrite ◽  
Crystallite Sizes ◽  
Co Precipitation

Nanostructured Mn-Zn ferrites were synthesized using co-precipitation in alkaline solution with different pH. The samples were characterized using X-ray diffraction (XRD), X-ray fluorescence (XRF), thermal analysis (TG-DTA), dynamic light scattering (DLS) and scanning electron microscopy (SEM) techniques. Monophasic nanoparticles were formed when synthesized with pH 10.5. This sample was heat-treated and its XRD data was refined by the Rietveld method. Mean crystallite sizes and microstrains were determined from X-ray line profile analysis using Single-Line and Warren-Averbach methods, which revealed a mean crystallite size of approximately 10 nm and negligible microstrains. Zn content was estimated using refined cell parameters, giving a value of 33 at %, in accordance with XRF result. TG-DTA revealed that the incorporation of α-Fe2O3 occurs around 1130 °C and 1200 °C with recrystallization of the Mn-Zn ferrite spinel phase. DLS showed that mean particle size increase with temperature up to 1159 nm at 800 °C. SEM analysis showed the samples agglomerate and present similar morphology with negligible size changing when calcined between 280 °C and 800 °C. However, the sample calcined at 1200 °C presents larger agglomerates due to the sintering process.

scholarly journals Effects of Gum Arabic-Coated Magnetite Nanoparticles on the Removal of Pb Ions from Aqueous Solutions

2021 ◽  
pp. 889-896
Author(s):  
Hanan J. Mustafa ◽  
Tagreed M. Al-Saadi
Keyword(s):  
Aqueous Solutions ◽  
Crystallite Size ◽  
Magnetite Nanoparticles ◽  
Gum Arabic ◽  
Xrd Analysis ◽  
Sem Analysis ◽  
Absorption Bands ◽  
X Ray ◽  
Ft Ir ◽  
Pb Ions

To study the removal of lead (Pb) ions from aqueous solutions, novel magnetite nanoparticles (NPs) of Ni0.31Mg0.15Ag0.04Fe2.5O4 were synthesized by coprecipitation synthesis using metal sulfates, and then coated with Gum Arabic (GA). The prepared NPs were analyzed using various spectroscopic and analytical methods, such as X-Ray diffraction analysis (XRD), Field Emission Scanning Electron Microscopy (FE-SEM), Energy Dispersive X-ray spectroscopy (EDX), Fourier Transform Infra-Red spectroscopy (FT-IR), and Atomic Absorption Spectrophotometer (AAS). By using XRD analysis, the cubic inverse spinel structure of the prepared NPs was proven, showing average values of crystallite size, lattice constant, and density of 28.57nm, 8.32582Å, and 5.2890 g/cm3, respectively. FE-SEM analysis revealed the sphere-like shape of the nanoparticles with a measured crystallite size of 25.93nm. The existence of constituent elements was evidenced by EDX. FT-IR test proved the success of the coating process of magnetite NPs by the presence of the main characteristic absorption bands of GA in the FT-IR spectrum of GA-magnetite NPs. The adsorption of Pb ions by GA- magnetite NPs was shown by AAS analysis, where the concentration of Pb ions decreased from 25ppm to 6.6ppm, reaching 1.1ppm at the time of 25min. The porosity of the NPs and the carboxyl groups in GA played an important role in the process.

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