scholarly journals Changes in the Structural and Morphological Parameters of Fe2O3/SiO2, as a Basis for the Electrode Material of Lithium Power Sources, Due to Shock-Vibrating Treatment

2019 ◽  
Vol 20 (4) ◽  
pp. 360-366
Author(s):  
Yu.V. Yavorskyi ◽  
Ya.V. Zaulychnyy ◽  
М.V. Karpets ◽  
А.B. Hrubiak ◽  
V.V. Moklyak ◽  
...  
Keyword(s):  
Structural Parameters ◽  
Interatomic Interaction ◽  
Coherent Scattering ◽  
Coherent Scattering Region ◽  
Electron Microscopic ◽  
Sem Images ◽  
Power Sources ◽  
Vibration Treatment ◽  
X Ray ◽  
Before And After

Using the method of X-ray diffraction, the effect of shock-vibration treatment on the structural parameters and phase composition of mixtures of silicon dioxide and alpha iron oxide was studied. From these results, has been found that the shock-vibration treatment of oxides mixture leads to an increase in the coherent scattering region of crystalline α-Fe2O3. We obtained SEM images of composites before and after treatment. From the SEM images it is seen that the processing is accompanied by fragmentation of the aggregates, uniform placement of the nanoparticles between each other and the formation of new denser agglomerates. Electron-microscopic study of mixtures using TEM was performed, which showed that the treatment leads to a lay-up of particles each other with the formation of interatomic interaction between them, which is consistent with the results of ultra-soft X-ray emission spectroscopy. The electrochemical properties of LPS, with electrodes based on mixtures before and after treatment, in galvanostatic mode were investigated. It is found that the charge capacity of the LPS with the electrode based on the mixture with the maximum concentration of α-Fe2O3 after treatment is reduced by half. 

scholarly journals The dependence between the structural-morphological features mixes 0.8SiO2/0.2Al2O3 from the time of mechanicall treatment

2021 ◽  
Vol 22 (3) ◽  
pp. 516-521
Author(s):  
Yu.V. Yavorsky' ◽  
Ya.V. Zaulichny ◽  
M.V. Karpets ◽  
A.I. Dudka ◽  
A.B. Hrubiak ◽  
...  
Keyword(s):  
Mechanical Treatment ◽  
Structural Parameters ◽  
Coherent Scattering ◽  
Lattice Parameter ◽  
Morphological Features ◽  
Sem Images ◽  
X Ray ◽  
Before And After ◽  
Perfect Mixing ◽  
The Relationship

This paper highlights the relationship between changes in structural and morphological features, electronic structure and exanging of time mechanical treatment at microbraker (MBT). Scaning electron microscopy revealed a change in the morphological features of nanoscale powders. From the comparison of SEM images of 0.8SiO2/0.2Al2О3 mixture before and after MBT, it is established that due to MBT, the agglomerates of the initial components are simultaneously crushed with perfect mixing particles of oxides between each other and the formation of new agglomerates with a denser structure. The increase in processing time leads to an increase in the density of the nanocomposite. The effect of time of mechanical treatment  on the structural parameters and phase composition of mixtures of silicon dioxide and titanium were studied using the method of X-ray structural analysis. The established agglomeration is accompanied by a change in the lattice parameter c with a change in the regions of coherent scattering of crystalline Al2О3. Ultra-soft X-ray emission spectroscopy was used to study the distribution of Op-, Sisd- and Alsd- valence electrons in 0.8SiO2/0.2Al2О3 powder mixtures after the different time of mechanicall treatment. An increase in atomic charges has been measured and can be explained by the transfer of electrons from Si and Al to O atoms in split Opπ-binding states.

Microstructural Changes in Co Films Depending on MOCVD Conditions

2015 ◽  
Vol 1085 ◽  
pp. 12-16
Author(s):  
Rustam Hairullin ◽  
Svetlana Dorovskikh
Keyword(s):  
Chemical Composition ◽  
Surface Morphology ◽  
Structural Parameters ◽  
Chemical Vapor ◽  
Coherent Scattering ◽  
Coherent Scattering Region ◽  
Organic Chemical ◽  
X Ray ◽  
Metal Organic ◽  
Phase And Chemical Composition

In this work the effect of substrate and vaporization temperatures on the structural parameters (sizes of coherent scattering region, values of strain), phase and chemical composition, surface morphology of Co films is revealed. Co films were deposited on Si (100) substrates by Metal-organic chemical vapor deposition using the diiminate complex Co (N’acN’ac)2 as a precursor. The sizes of coherent scattering region, values of strain and phase composition of Co films were determined by the X-ray diffraction analysis. The chemical composition was identified by the Energy-dispersive X-ray spectroscopy. The surface morphology of Co films was investigated by scanning electron microscope. It is found that the variation of deposition conditions allows us widely to change structural parameters and chemical composition of Co films.

Photocatalytic Activity of Sol-Gel Derived Bi2O3-TiO2 Nanocomposite

2012 ◽  
Vol 712 ◽  
pp. 73-83 ◽  
Author(s):  
C. Karunakaran ◽  
P. Magesan ◽  
P. Gomathisankar
Keyword(s):  
Visible Light ◽  
Deep Level ◽  
Anatase Phase ◽  
Sol Gel ◽  
Spherical Shape ◽  
Tween 80 ◽  
Electron Microscopic ◽  
Sem Images ◽  
X Ray ◽  
Crystallite Sizes

Bi2O3-TiO2 nanocomposites were obtained by sol-gel method using tween 80 (T-80) or polyvinyl pyrrolidone-polyethylene glycol (PVP-PEG) as templating agent. The powder X-ray diffraction (XRD) patterns of both the composites reveal the crystal structure of Bi2O3 as primitive tetragonal and TiO2 is in anatase phase. The energy dispersive X-ray (EDX) spectra provide the composition of Bi2O3 in Bi2O3-TiO2 (T-80) and Bi2O3-TiO2 (PVP-PEG) as 3.8 and 20.4 mol. %, respectively. The average crystallite sizes of Bi2O3-TiO2 (T-80) and Bi2O3-TiO2 (PVP-PEG), derived from XRD, are 9 and 17 nm, respectively. The scanning electron microscopic (SEM) images show the spherical shape of Bi2O3-TiO2 (T-80) and the composites are polycrystalline. The diffuse reflectance spectra (DRS) of the composites display faint absorption of visible light and strong absorption in UV-A region. The photoluminescence (PL) spectra of both the composites are similar and the observed near band gap emission (NBE) and deep level emission (DLE) agree with those of TiO2. The impedance spectra show that the charge-transfer resistances of the composites do not differ significantly. The visible light photoimpedance spectra display the photoconductance of Bi2O3-TiO2 (PVP-PEG) but not that of Bi2O3-TiO2 (T-80). Although the visible light-photocatalytic activities of the two nanocomposites to degrade dye do not differ significantly Bi2O3-TiO2 (T-80) under UV-A light degrades dyes faster than Bi2O3-TiO2 (PVP-PEG).

REMOVAL OF THE SURFACTANT SURROUNDING Ag NANOCLUSTERS SYNTHESIZED BY NEW THERMAL DECOMPOSITION METHOD

2002 ◽  
Vol 01 (05n06) ◽  
pp. 477-481 ◽  
Author(s):  
LEE DON KEUN ◽  
YOUNG SOO KANG
Keyword(s):  
Thermal Decomposition ◽  
Silver Nanoclusters ◽  
X Ray Diffraction ◽  
Electron Microscopic ◽  
Sem Images ◽  
X Ray ◽  
Transmission Electron ◽  
Thermo Gravimetric Analyzer ◽  
Ft Ir ◽  
Complex Transmission

Silver nanoclusters have been formed by thermal decomposition of Ag-oleate complex. Transmission electron microscopic (TEM) images of the particles showed two-dimensional assembly of particles with diameter of 10.5 nm. Energy-dispersive X-ray (EDX) spectrum and X-ray diffraction (XRD) peaks of the nanoclusters showed the highly crystalline nature of the silver structures. The decomposition of silver-oleate complex was analyzed by Thermo Gravimetric Analyzer (TGA) and the crystallization process was observed by XRD. The removal of the surfactant surrounding silver nanoclusters was measured by FT-IR and SEM images.

Annealing Effects on the Properties of Electrodeposited CdSSe Thin Films

2011 ◽  
Vol 15 (1) ◽  
pp. 43-48
Author(s):  
T. Mahalingam ◽  
V. Dhanasekaran ◽  
S. Rajendran ◽  
G. Ravi ◽  
Luis Ixtlilco ◽  
...  
Keyword(s):  
Thin Films ◽  
Annealing Temperature ◽  
Complex Refractive Index ◽  
Optical Transmittance ◽  
Hexagonal Structure ◽  
Electron Microscopic ◽  
X Ray ◽  
Before And After ◽  
Annealing Effects ◽  
Scanning Electron

The effect of post heat treatment on structural, morphological and optical properties of electrodeposited CdSSe solid solution thin films were studied using X-ray diffractometer (XRD), scanning electron microscopy (SEM), and UV-Vis-NIR spectrophotometer, respectively. X-ray diffraction patterns revealed that polycrystalline nature with hexagonal structure of CdSSe thin films. Also the microstructural properties are calculated tends to increase and the face centred hexagonal orientation of CdSSe thin film is enhanced significantly by increasing the annealing temperature. Scanning electron microscopic images revealed that the hexagonal shaped grains are occupying the entire surface of the film. The optical transmittance and absorption spectra were recorded in the range 400 to1100 nm. The band gap of the CdSSe thin films was found to decrease from 2.0 eV to 1.8 eV due to annealing temperature. The real part of the complex refractive index (n) and the imaginary part extinction coefficient (k) were calculated before and after annealing.

The Surface Chemistry Characterization of Pyrite, Sphalerite and Molybdenite after Bioleaching

2017 ◽  
Vol 262 ◽  
pp. 487-491 ◽  
Author(s):  
Sina Ghassa ◽  
Hadi Abdollahi ◽  
Mahdi Gharabaghi ◽  
Saeed Chehreh Chelgani ◽  
Mohammad Jafari
Keyword(s):  
Surface Chemistry ◽  
Dissolution Kinetics ◽  
X Ray Diffraction ◽  
Sem Images ◽  
Chemical Leaching ◽  
Characterization Methods ◽  
X Ray ◽  
Ash Layer ◽  
Before And After

The mineral surface chemistry characterization is essential to describe the dissolution kinetics in leaching and bioleaching. Five different methods, including X-ray diffraction (XRD), Scanning Electron Microscopy (SEM), Energy-Dispersive X-ray Spectroscopy (EDS), Fourier Transform Infrared Spectroscopy (FTIR) and Raman Spectroscopy, have been applied to study the surface chemistry changes during pyrite, sphalerite and molybdenite bioleaching. The surface characterizations have been done for samples before and after biological and chemical leaching. The SEM images illustrated that the minerals surfaces were smooth before processing, while they covered with an ash layer after biological treatment. Although EDS analysis and Raman spectrum demonstrated the potassium jarosite formation on the pyrite surface during bioleaching, the formation of jarosite layer did not occur on the sphalerite surfaces during bioleaching. On the other hand, a sulfur layer formation on the sphalerite surface was confirmed by mentioned characterization methods. Finally, according to the XRD and EDS spectrum the molybdenite surface had been covered both with sulfur and jarosite.

scholarly journals The Comparative PDT Experiment of the Inactivation of HL60 on Modified TiO2Nanoparticles

2015 ◽  
Vol 2015 ◽  
pp. 1-8 ◽  
Author(s):  
Kaiqi Lu ◽  
Qiyun He ◽  
Li Chen ◽  
Baoquan Ai ◽  
Jianwen Xiong
Keyword(s):  
Electron Microscope ◽  
Leukemia Cells ◽  
X Ray Diffraction ◽  
Sem Images ◽  
X Ray ◽  
Ultrasonic Methods ◽  
Photocatalytic Inactivation ◽  
Before And After ◽  
Inactivation Effect ◽  
Scanning Electron

Four samples of modified titanium dioxide (TiO2), Fe/TiO2(2 wt%), Fe/TiO2(5 wt%), and 5-ALA/TiO2, were experimented in photodynamic therapy (PDT) on leukemia cells HL60, performing promising photocatalytic inactivation effect. Fe/TiO2and 5-ALA/TiO2were synthesized in methods of precipitation and ultrasonic methods, respectively. X-ray diffraction spectra and UV-Vis spectra were studied for the samples’ crystalline phase and redshift of absorption peak. Further, FTIR spectra and Raman spectra were obtained to examine the combination of 5-aminolevulinic (5-ALA) and TiO2nanoparticles. The toxicity of these four kinds of nanoparticles was studied through darkroom experiments. And based on the concentration which caused the same toxic effect (90%) on HL60, PDT experiments of TiO2, Fe/TiO2(2%), Fe/TiO2(5%), and ALA/TiO2were done, resulting in the fact that the photokilling efficiency was 69.7%, 71.6%, 72%, and 80.6%, respectively. Scanning electron microscope (SEM) images of the samples were also taken to study the morphology of HL60 cells before and after PDT, resulting in the fact the activation of the modified TiO2from PDT was the main cause of cell apoptosis.

Structure of Feroxyhite as Determined by Simulation of X-Ray Diffraction Curves

Clay Minerals ◽  
1993 ◽  
Vol 28 (2) ◽  
pp. 209-222 ◽  
Author(s):  
V. A. Drits ◽  
B. A. Sakharov ◽  
A. Manceau
Keyword(s):  
Structural Parameters ◽  
Stacking Faults ◽  
Site Occupancy ◽  
Volume Ratio ◽  
Coherent Scattering ◽  
Close Packing ◽  
X Ray Diffraction ◽  
X Ray ◽  
Octahedral Sites ◽  
Atomic Coordinates

AbstractPowder X-ray diffraction (XRD) curves were calculated for the different structural models so far proposed for feroxyhite (δFeOOH). The influence on XRD features of different structural parameters, including site occupancy of Fe atoms, atomic coordinates, content and distribution of stacking faults, and dimension of coherent scattering domains, were considered. On the basis of agreement between experimental and simulated curves it is shown that δFeOOH is a mixture of feroxyhite proper and ultradispersed hematite in the 9 : 1 volume ratio. Feroxyhite proper consists of hexagonal close packing of anions containing 5% stacking faults. Iron atoms occupy only octahedral sites and are distributed in such a way that face-sharing filled octahedral pairs regularly alternate with vacant octahedral pairs along the c axis. This distribution of Fe atoms is quite similar to that established by Patrat et al. (1983), but in each pair, Fe atoms are displaced by the same value of 0.3 Å in opposite directions away from the centre of their octahedron. Nearest Fe-Fe distances calculated for the model proposed (2.88, 3.01, 3-39 and 3-73 Å) practically coincide with those found by EXAFS spectroscopy for the same sample (2-91, 3.04, 3.41 and 3.7-3.8 Å).

The effect of hydrochloric acid (HCl) on permanent molars: A scanning electron microscope (SEM) and energy dispersive X-ray spectroscopy (EDS) study

2020 ◽  
Vol 60 (3) ◽  
pp. 172-181
Author(s):  
Christine Jones ◽  
Tammy Bracewell ◽  
Aida Torabi ◽  
Claudia C Beck ◽  
Taylor B Harvey
Keyword(s):  
Hydrochloric Acid ◽  
Energy Dispersive ◽  
Dissolution Time ◽  
Dental Tissue ◽  
Sem Images ◽  
X Ray ◽  
Eds Analysis ◽  
Before And After ◽  
Permanent Molars ◽  
Scanning Electron

It is well established that acid disposal is a potentially effective method used by criminal syndicates to hinder the identification of victims. This study documents the effects of continuous immersion in hydrochloric acid (HCl, 37%) on molars using macroscopic analysis, scanning electron microscopy (SEM), and energy dispersive X-ray spectroscopy (EDS). The goal of this study is to aid in distinguishing visually unrecognizable fragments of dental remains when drastic changes in morphology have occurred as a result of acid exposure. Macroscopic, SEM, and EDS analysis were conducted on seven maxillary molars before and after HCl treatment. Molars reduced in weight relative to the length of time immersed in HCl and the dissolution time was over 40 hours longer than reported in previous studies, at just over 66 hours. SEM and EDS analysis showed acid-treated teeth exhibited morphological patterns such as cracking and layering visible at high magnification. Calcium/phosphorous ratios fell within the expected range of 1.6–2.5, indicating that HCl-treated teeth are still identifiable as osseous or dental tissue even when not visually identifiable as teeth. This is the first study to present SEM images of molar cementum before and after immersion in HCl and to present EDS results. This information can assist researchers and investigators in determining the presence of dental tissue in a forensic context associated with acid disposal.

MID-IR Photodetectors Based on InAs/InGaSb Type-II Quantum Wells

1997 ◽  
Vol 484 ◽  
Author(s):  
G. J. Brown ◽  
M. Ahoujja ◽  
F. Szmulowicz ◽  
W. C. Mitchel ◽  
C. H. Lin
Keyword(s):  
Quantum Wells ◽  
Band Gap ◽  
Energy Band ◽  
Structural Parameters ◽  
X Ray Diffraction ◽  
Energy Band Gap ◽  
X Ray ◽  
Hall Measurements ◽  
Before And After ◽  
Order Of Magnitude

AbstractWe report on the growth and characterization of InAs/InxGal..Sb strained-layer superlattices (SLS) designed with a photoresponse cut-off wavelength of IOlim. The structural parameters, layer thicknesses and compositions, were chosen to optimize the infrared absorption for a superlattice with an energy band gap of 120 meV. The energy band structure and optimized absorption coefficient were determined with an 8×8 envelope function approximation model. The superlattices were grown by molecular beam epitaxy and were comprised of 100 periods of 43.6Å InAs and 17.2Å In.23Ga.77Sb lattice-matched to the GaSb substrates. In order to reduce the background carrier concentrations in this material, superlattices grown with different substrate temperatures were compared before and after annealing. This set of superlattice materials was characterized using x-ray diffraction, photoresponse and Hall measurements. The measured photoresponse cut-off energies of 116 ± 6 meV is in good agreement with the predicted energy band gap for the superlattice as designed. The intensity of the measured mid-infrared photoresponse was found to improve by an order of magnitude for the superlattice grown at the lower substrate temperature and then annealed at 520 °C for 10 minutes. However, the x-ray diffraction spectra were very similar before and after annealing. The temperature dependent Hall measurements at low temperatures (<25K) were dominated by holes with quasi two-dimensional behavior. An admirably low background carrier concentration of 1×1012 cm−2 was measured at low temperature.

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