scholarly journals Study on the Structure and Morphology of Iron Nanopowders Obtained by the Method of Electric Explosion of Wires

2016 ◽  
Vol 18 (1) ◽  
pp. 3
Author(s):  
G. Partizan ◽  
B.Z. Mansurov ◽  
B.S. Medyanova ◽  
А.B. Koshanova ◽  
M.E. Mansurova ◽  
...  
Keyword(s):  
Crystal Lattice ◽  
Computer Experiments ◽  
Spherical Shape ◽  
Average Diameter ◽  
Electric Explosion ◽  
Transmission Electron ◽  
Explosive Evaporation ◽  
Diffraction Patterns ◽  
Good Agreement ◽  
Comprehensive Study

This article presents the results of comprehensive study on the structure and<br />morphology of iron nanopowders synthesized by electric explosive evaporation of<br />metal wire. The results of scanning and transmission electron microscopy showed<br />that nanoclusters have a spherical shape with an average diameter of 65 nm. It<br />was revealed based on the analysis of the diffraction patterns that nanoparticles of<br />nanopowders obtained in electric explosion have a crystal lattice with a parameter<br />less than a standard cell. The results of computer experiments are in good agreement<br />with the findings of X-ray analysis. However, the question about the reasons of<br />distortion of the crystal lattice of nanoclusters remains controversial.

Calorimetric Analysis of Precipitation in Undercooled Ni-Si Alloy

2013 ◽  
Vol 307 ◽  
pp. 352-357
Author(s):  
Kai Fan ◽  
Feng Liu ◽  
Bao Quan Fu ◽  
Wen Zhong Luo ◽  
Yao He Zhou
Keyword(s):  
Electron Microscopy ◽  
Exothermic Reaction ◽  
Spherical Shape ◽  
Precipitate Size ◽  
Precipitation Process ◽  
Calorimetric Analysis ◽  
Shape Model ◽  
Transmission Electron ◽  
Isothermal Measurements ◽  
Good Agreement

In order to study the precipitaion of Ni3Si particle in undercooled Ni-Si alloy, calorimetric analyses were carried out using non-isothermal measurements by DSC. The scanning electron microscopy (SEM) and the transmission electron microscopy (TEM) measurements were used to describe qualitatively and quantitatively the precipitate microstructures. The non-isothermal DSC thermograms exhibited one reaction peaks and it indicated that the precipitation process is an exothermic reaction. The evolution for the precipitate was obtained in the as-solidified Ni-Si alloy subjected to DT=195K, meanwhile, the precipitate size was found increased with decreased heating rate in the TEM images. The largest precipitate size was about 120nm, and the precipitates still kept spherical shape. Model prediction for the precipitation of Ni3Si particle has been performed. Good agreement with experimental data has been achieved

scholarly journals A Study On Dispersion Stability Of Nickel Nanoparticles Synthesized By Wire Explosion In Liquid Media

2015 ◽  
Vol 60 (2) ◽  
pp. 1379-1382 ◽  
Author(s):  
C.K. Kim ◽  
G.-J. Lee ◽  
M.K. Lee ◽  
C.K. Rhee
Keyword(s):  
Nickel Nanoparticles ◽  
Spherical Shape ◽  
Physical Method ◽  
Average Diameter ◽  
Dispersion Stability ◽  
Wire Explosion ◽  
Transmission Electron ◽  
One Step ◽  
Polymer Surfactant ◽  
Microscopy Images

Abstract In this study, nickel nanoparticles were synthesized in ethanol using portable pulsed wire evaporation, which is a one-step physical method. From transmission electron microscopy images, it was found that the Ni nanoparticles exhibited a spherical shape with an average diameter of 7.3 nm. To prevent aggregation of the nickel nanoparticles, a polymer surfactant was added into the ethanol before the synthesis of nickel nanoparticles, and adsorbed on the freshly synthesized nickel nanoparticles during the wire explosion. The dispersion stability of the prepared nickel nanofluids was investigated by zeta-potential analyzer and Turbiscan optical analyzer. As a result, the optimum concentration of polymer surfactant to be added was suggested for the maximized dispersion stability of the nickel nanofluids.

Fabrication and Electrical Characterization of Metal-Silicide Nanocrystals for Nano Floating Gate Nonvolatile Memory

2009 ◽  
Vol 1160 ◽  
Author(s):  
Seung Jong Han ◽  
Ki Bong Seo ◽  
Dong Uk Lee ◽  
Eun Kyu Kim ◽  
Se-Mam Oh ◽  
...  
Keyword(s):  
Nonvolatile Memory ◽  
Electrical Characterization ◽  
Spherical Shape ◽  
Average Diameter ◽  
Floating Gate ◽  
Flat Band ◽  
Hysteresis Curve ◽  
Flat Band Voltage ◽  
Transmission Electron ◽  
Floating Gate Memory

AbstractWe have fabricated the nano-floating gate memory with the TiSi2 and WSi2 nanocrystals embedded in the dielectrics. The TiSi2 and WSi2 nanocrystals were created by using sputtering and rapidly thermal annealing system, and then their morphologies were investigated by transmission electron microscopy. These nanocrystals have a spherical shape with an average diameter of 2-5 nm. The electrical properties of the nano-floating gate memory with TiSi2 and WSi2 nanocrystals were characterized by capacitance-voltage (C-V) hysteresis curve, memory speed and retention. The flat-band voltage shifts of the TiSi2 and WSi2 nanocrystals capacitors obtained appeared up to 4.23 V and 4.37 V, respectively. Their flat-band voltage shifts were maintained up to 1.6 V and 1 V after 1 hr.

scholarly journals BIODEGRADABLE GELATIN DECORATED Fe3O4 NANOPARTICLES FOR PACLITAXEL DELIVERY

2018 ◽  
Vol 55 (1B) ◽  
pp. 7 ◽  
Author(s):  
Dai Hai Nguyen
Keyword(s):  
Fe3o4 Nanoparticles ◽  
Drug Loading ◽  
Spherical Shape ◽  
Average Diameter ◽  
Precipitation Method ◽  
Loop Analysis ◽  
Transmission Electron ◽  
Potential Applications ◽  
Size And Morphology ◽  
Co Precipitation

The objective of this study is to prepare biodegradable iron oxide nanoparticles with gelatin (GEL) for paclitaxel (PTX) delivery. In detail, Fe3O4 nanoparticles were prepared and then coated them with GEL (Fe3O4@GEL) conjugate by co–precipitation method. Furthermore, the formation of Fe3O4@GEL was demonstrated by Fourier transform infrared (FT–IR) and powder X–ray diffraction (XRD). The superparamagnetic property of Fe3O4@GEL was also showed by hysteresis loop analysis, the saturation magnetization reached 20.36 emu.g–1. In addition, size and morphology of Fe3O4@GEL nanoparticles were determined by transmission electron microscopy (TEM). The results indicated that Fe3O4@GEL nanoparticles were spherical shape with average diameter of 10 nm. Especially, PTX was effectively loaded into the coated magnetic nanoparticles, 86.7 ± 3.2 % for drug loading efficiency and slowly released up to 5 days. These results suggest that the potential applications of Fe3O4@GEL nanoparticles in the development of stable drug delivery systems for cancer therapy.

scholarly journals Synthesis of bismuth ferrite nanopowder doped with erbium ions

2021 ◽  
Vol 23 (1) ◽  
Author(s):  
Elena V. Tomina ◽  
Anna A. Pavlenko ◽  
Nikolay A. Kurkin
Keyword(s):  
Crystal Lattice ◽  
Spray Pyrolysis ◽  
Bismuth Ferrite ◽  
Morphological Characteristics ◽  
Spherical Shape ◽  
Information Storage ◽  
X Ray ◽  
Erbium Ions ◽  
Diffraction Patterns ◽  
Real Composition

The potential for the practical application of bismuth ferrite (BFO) in information storage, microelectronic, and spintronic devices and in medical sensors of various purpose is limited by the presence of a spin cycloid. Its destruction, including destruction due to doping with rare earth elements and the transfer of BFO to a nanoscale state, contributes to the occurrence of ferromagnetism and the manifestation of the magnetoelectric effect. The study was aimed at the synthesis of bismuth ferrite nanopowder doped with erbium ions.By spray pyrolysis at a temperature of 760 °C, we synthesised BFO samples with a nominal degree of doping with erbium ions from 0.05 to 0.20. The data of X-ray diffraction analysis show that there is a small amount of Bi25FeO39 and Bi2Fe4O9 in the doped samples.The shift of the BFO reflections on diffraction patterns towards larger 2q angles is representative of the incorporation of erbium ions into the crystal lattice of BiFeO3. The morphological characteristics of the samples were determined using transmission electron microscopy. According to the data of electron probe X-Ray microanalysis, the real composition of the doped ErxBi1-xFeO3 samples is very close to the nominal.The particles of ErxBi1-xFeO3 powders synthesised by spray pyrolysis have a nearly spherical shape, the particle-size distribution is in the range of 5–300 nm, the predominant number of particles have a size in the range of 50-200 nm, and the agglomeration is weak. The decrease in the crystal lattice parameters and the unit cell volume of ErxBi1-xFeO3 and an increase in the degree of doping with erbium ions confirm the incorporation of Er3+ into the BFO crystal lattice to the bismuth position.

scholarly journals Nanocrystallization of Anthocyanin Extract from Red-Fleshed Apple ′QN-5′ Improved Its Antioxidant Effect through Enhanced Stability and Activity under Stressful Conditions

Molecules ◽  
2019 ◽  
Vol 24 (7) ◽  
pp. 1421 ◽  
Author(s):  
Xiang Zhang ◽  
Heqiang Huo ◽  
Xiaohong Sun ◽  
Jun Zhu ◽  
Hongyi Dai ◽  
...  
Keyword(s):  
Storage Time ◽  
Spherical Shape ◽  
Average Diameter ◽  
Anthocyanin Content ◽  
Capacity Loss ◽  
Transmission Electron ◽  
Scavenging Capacity ◽  
Alkaline Conditions ◽  
Regular Spherical Shape ◽  
Scavenging Rates

Red-flesh apples are known as functional fruits because of their rich anthocyanin. The anthocyanin content of the red flesh apple cultivar ′QN-5′ we bred can reach 361 mg·kg−1 (FW), and showed higher scavenging capacity to DPPH radicals, hydroxyl radicals, and superoxide anion radicals, with scavenging rates of 80.0%, 54.0%, and 43.3%, respectively. We used this particular anthocyanin-rich ′QN-5′ apple as material to examine how nanocrystallization affects the antixodiant effect of anthocyanin. The anthocyanin extract was encapsulated with biocompatible zein to form zein-anthocyanin nanoparticles (ZANPs). Transmission electron microscopy (TEM) scanning showed that ZANPs had a regular spherical shape with an average diameter size of 50–60nm. When the ratio of the zein and the anthocyanin was 1:0.5, the results suggested that the encapsulation efficiency (EE) of the ZANPs could reach as high as 92.8%, and that scavenging rate for DPPH radicals was increased from 87.1% to 97.2% compared to the non-nanocrystallized anthocyanin extract. Interestingly, treatment under alkaline conditions (pH 9.0), high temperature (90 °C), and a storage time of 7 days could decrease the scavenging capacity of the ZANPs for DPPH radicals, but this scavenging capacity loss for ZANPs was significantly lower than that observed in the non-nanocrystallized anthocyanin, suggesting the higher stability of ZANPs is caused by encapsulation. These results would provide a theoretical basis for the application of the anthocyanin in scavenging free radicals under stress conditions.

Gold Nanoparticles Supported on SrTiO3 by Solution Plasma Sputter Deposition for Enhancing UV- and Visible-light Photocatalytic Efficiency

2013 ◽  
Vol 1509 ◽  
Author(s):  
Gasidit Panomsuwan ◽  
Nobuyuki Zettsu ◽  
Nagahiro Saito
Keyword(s):  
Visible Light ◽  
Au Nanoparticles ◽  
Spherical Shape ◽  
Average Diameter ◽  
Sputter Deposition ◽  
Transmission Electron ◽  
One Step ◽  
Blue Solution ◽  
Photocatalytic Applications ◽  
Visible Light Photocatalytic

ABSTRACTGold (Au) nanoparticles were synthesized and deposited on the perovskite SrTiO3 (STO) via a one-step solution plasma sputter deposition (SPSD) without any reducing reagents at ambient condition. Good dispersion of the Au nanoparticles deposited on the STO surface was clearly observed. The synthesized Au nanoparticles were well-crystallized with a spherical shape and preferably exhibited multiply twinned structure. An average diameter of Au nanoparicles was estimated to be 6.1 ± 1.4 nm by transmission electron microscopy. Enhanced photocatalytic activity was found for the Au-STO when compared to the pure STO, as investigated from the degradation of methylene blue solution under ultraviolet and visible light irradiation. The SPSD seems to be a rapid and facile approach to prepare the Au nanoparticles supported on the metal oxide for photocatalytic applications.

X-Ray Scattering (Modeling and Experiment) of InxGa1-xAs/GaAs Multiple Quantum Wells

1987 ◽  
Vol 103 ◽  
Author(s):  
Jichai Jeong ◽  
J. C. Lee ◽  
M. A. Shahid ◽  
T. E. Schlesinger ◽  
A. G. Milnes
Keyword(s):  
Quantum Well ◽  
Quantum Wells ◽  
Multiple Quantum ◽  
X Ray Diffraction ◽  
Quantum Well Structures ◽  
X Ray ◽  
X Ray Scattering ◽  
Transmission Electron ◽  
Diffraction Patterns ◽  
Good Agreement

ABSTRACTX-ray diffraction, transmission electron microscopy (TEM), and photoluminescence measurements have been made on strained InxGa1-xAs/GaAs quantum well structures. The well widths measured from TEM are 187, 115 and 69 Å for an interrupted growth, and 218, 126, 60 Å for a non-interrupted growth. In the measured x-ray diffraction patterns, the Pendellosung fringes due to GaAs barriers are modulated by a broad weak peak mostly coming from the thickest InxGa1-xAs well layer and is fairly symmetric for the noninterrupted sample. For the interrupted quantum well, the x-ray diffraction pattern is less symmetric, since there is further modulation by another broader and weaker peak. This results show that the In content in the InxGa1-xAs well layers are not well controlled for the interrupted quantum well. Using actual thickness measured from TEM, x-ray diffraction patterns are calculated and good agreement is obtained between the measured and the calculated x-ray diffraction patterns. The three strained InxGa1-xAs/Gaks quantum wells grown without interruption produce high intensity and narrow full-width at half-maximum (FWHIM) of 2.9 meV of the photoluminescence peak. The photoluminescence peaks for the interrupted quantum well are relatively broad and asymmetric, and have lower intensities, indicating that better quality InxGa1-xAs/GaAs quantum wells can be grown without interruption.

Hydrothermal Synthesis of Carbon Quantum Dots from Persimmons as Probe for Determination of Ferric Ions

2021 ◽  
Vol 21 (3) ◽  
pp. 1728-1734
Author(s):  
Yingte Wang ◽  
Yujie Yang ◽  
Xiaoyue Chang ◽  
Rong Duan ◽  
Yong Zhang
Keyword(s):  
Quantum Dots ◽  
Spherical Shape ◽  
Average Diameter ◽  
Carbon Quantum Dots ◽  
Excitation Wavelength ◽  
Blue Fluorescence ◽  
Environment Friendly ◽  
Transmission Electron ◽  
Relative Standard

Local natural persimmons were used as a new precursor to synthesize carbon quantum dots (CQDs) by a brief and environment friendly strategy, hydrothermal method. The as-prepared CQDs were characterized by transmission electron microscopy, Fourier transform infrared spectroscopy, Ultraviolet-visible spectroscopy, as well as fluorescence spectrophotometer. The average diameter of CQDs was 2.5±0.5 nm with spherical shape and exhibited blue fluorescence with the maximum emission wavelength at 438 nm and excitation wavelength at 345 nm. The influences of pH and ionic strength on CQDs fluorescence were evaluated. Moreover, the CQDs were used for determination of Fe3+ by blue fluorescence quenching as the result of the interaction between Fe3+ and –OH, –COOH on the CQDs surfaces. The proposed CQDs displayed high selectivity and sensitivity of Fe3+ in comparison with other metal ions. Therefore, a good linear relationship was established with the Fe3+ concentration in the range of 0.6–400 μM. The correlation coefficient of the calibration curve was 0.996. The detection limit of the method was 0.56 μM. Eventually, the CQDs made from persimmons were used for determination of Fe3+ in actual water sample with satisfactory results and gave recoveries between 95.66% and 99.90%. The relative standard deviation was 1.20%–1.86%. The results demonstrated the potential towards diverse applications of the local persimmons.

Material Characterization of Plasma-Treated Aluminum Particles via Different Gases

MRS Advances ◽  
2019 ◽  
Vol 4 (27) ◽  
pp. 1589-1595
Author(s):  
Chi-Chin Wu ◽  
Kelsea K. Miller ◽  
Scott D. Walck ◽  
Michelle Pantoya
Keyword(s):  
Surface Passivation ◽  
Plasma Reactor ◽  
Particle Surface ◽  
Average Diameter ◽  
Atmospheric Plasma ◽  
Iodic Acid ◽  
Transmission Electron ◽  
Active Aluminum ◽  
Diffraction Patterns ◽  
Surface Morphologies

ABSTRACTThis work describes exploration of mitigating the parasitic amorphous alumina (Al2O3) shell of aluminum nanoparticles (n-Al) and modifying the surface using different plasmas, leading to n-Al with thinner shell and different coatings including carbons and oxidizing salt called aluminum iodate hexahydrate (AIH), respectively. The approach exploits a prototype atmospheric non-thermal plasma reactor with dielectric barrier discharge (DBD) configuration for nanoparticle surface modifications using n-Al of 80 nm average diameter as an example. Preliminary results indicate that the amorphous Al2O3 shell surrounding the active aluminum core can be mitigated with inert plasmas by as much as 40% using either helium (He) or argon (Ar). The particle surface becomes carbon-rich with carbon monoxide (CO) / He plasmas. By immersing the plasma-treated n-Al in an iodic acid (HIO3) solution, AIH crystals can be formed on the n-Al surface. Transmission electron microscopy (TEM) is used as a major tool to study the details of the modified surface morphologies, diffraction patterns, and chemical composition of the modified n-Al. The results demonstrate effective surface passivation of n-Al via atmospheric plasma techniques.

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