Artificial silver sulfide Ag2S: Crystal structure and particle size in deposited powders

2015 ◽  
Vol 83 ◽  
pp. 35-47 ◽  
Author(s):  
S.I. Sadovnikov ◽  
A.I. Gusev ◽  
A.A. Rempel
Keyword(s):  
Crystal Structure ◽  
Particle Size ◽  
Silver Sulfide

Microstructure Characterization of Ag Nanoparticles Prepared by Hydrothermal Method

2012 ◽  
Vol 476-478 ◽  
pp. 1138-1141
Author(s):  
Zhi Qiang Wei ◽  
Qiang Wei ◽  
Li Gang Liu ◽  
Hua Yang ◽  
Xiao Juan Wu
Keyword(s):  
Crystal Structure ◽  
Particle Size ◽  
Hydrothermal Method ◽  
Ag Nanoparticles ◽  
Average Particle Size ◽  
Average Particle ◽  
Face Centered Cubic ◽  
Selected Area Electron Diffraction ◽  
Transmission Electron ◽  
Face Centered

Ag nanoparticles were successfully synthesized by hydrothermal method under the polyol system combined with traces of sodium chloride, Silver nitrate(AgNO3) and polyvinylpyrrolidone (PVP) acted as the silver source and dispersant respectively. The samples by this process were characterized via X-ray powder diffraction (XRD), Brunauer–Emmett–Teller (BET) adsorption equation, transmission electron microscopy (TEM) and the corresponding selected area electron diffraction (SAED) to determine the chemical composition, particle size, crystal structure and morphology. The experiment results indicate that the crystal structure of the samples is face centered cubic (FCC) structure as same as the bulk materials, The specific surface area is 24 m2/g, the particle size distribution ranging from10 to 50 nm, with an average particle size about 26 nm obtained by TEM and confirmed by XRD and BET results.

scholarly journals Synthesis of magnesium carbonate hydrate from natural talc

2020 ◽  
Vol 18 (1) ◽  
pp. 951-961
Author(s):  
Qiuju Chen ◽  
Tao Hui ◽  
Hongjuan Sun ◽  
Tongjiang Peng ◽  
Wenjin Ding
Keyword(s):  
Crystal Structure ◽  
Particle Size ◽  
Crystal Growth ◽  
Crystal Morphology ◽  
Magnesium Carbonate ◽  
Organic Additives ◽  
X Ray Diffraction ◽  
Morphological Transformation ◽  
X Ray ◽  
Carbonation Process

AbstractVarious morphologies of magnesium carbonate hydrate had been synthesized without using any organic additives by carefully adjusting the reaction temperature and time during the talc carbonation process. At lower temperatures, magnesium carbonate hydrate was prone to display needle-like morphology. With the further increase of the carbonation temperature, the sheet-like crystallites became the preferred morphology, and at higher aging temperatures, these crystallites tended to assemble into layer-like structures with diverse morphologies, such as rose-like particles and nest-like structure. The reaction time had no effect on the crystal morphology, but it affected the particle size and situation of the crystal growth. X-Ray diffraction results showed that these various morphologies were closely related to their crystal structure and compositions. The needle-like magnesium carbonate hydrate had a formula of MgCO3·3H2O, whereas with the morphological transformation from needle-like to sheet-like, rose-like, and nest-like structure, their corresponding compositions also changed from MgCO3·3H2O to 4MgCO3·Mg(OH)2·8H2O, 4MgCO3·Mg(OH)2·5H2O, and 4MgCO3·Mg(OH)2·4H2O.

Fabrication of Nanostructured Fe-Co Alloy Powders by Hydrogen Reduction and Its Magnetic Properties

2007 ◽  
Vol 534-536 ◽  
pp. 1389-1392
Author(s):  
Young Jung Lee ◽  
Baek Hee Lee ◽  
Gil Su Kim ◽  
Kyu Hwan Lee ◽  
Young Do Kim
Keyword(s):  
Crystal Structure ◽  
Particle Size ◽  
Grain Size ◽  
Magnetic Properties ◽  
Nanostructured Materials ◽  
Hydrogen Reduction ◽  
Internal Strain ◽  
Oxide Powder ◽  
Powder Mixtures ◽  
Effect Of Microstructure

Magnetic properties of nanostructured materials are affected by the microstructures such as grain size (or particle size), internal strain and crystal structure. Thus, it is necessary to study the synthesis of nanostructured materials to make significant improvements in their magnetic properties. In this study, nanostructured Fe-20at.%Co and Fe-50at.%Co alloy powders were prepared by hydrogen reduction from the two oxide powder mixtures, Fe2O3 and Co3O4. Furthermore, the effect of microstructure on the magnetic properties of hydrogen reduced Fe-Co alloy powders was examined using XRD, SEM, TEM, and VSM.

Effect of Iron Substitution on Structure and Optical Properties of Nanocrystalline CaTiO3

2008 ◽  
Vol 3 ◽  
pp. 123-128 ◽  
Author(s):  
A. Bandyopadhyay ◽  
S. Mondal ◽  
M. Pal ◽  
Umapada Pal ◽  
M. Pal
Keyword(s):  
Crystal Structure ◽  
Particle Size ◽  
Iron Concentration ◽  
Rietveld Analysis ◽  
Exothermic Peak ◽  
Optical And Electrical Properties ◽  
X Ray Diffraction ◽  
Chemical Route ◽  
X Ray ◽  
Soft Chemical Route

Nanocrystalline CaTiO3 powders doped with Fe2O3 have been prepared using a soft chemical route. Precipitation of CaTiO3 nanocrystals has been studied by monitoring the exothermic peak in their DSC spectra. The crystal growth temperature of the samples depends on the concentration of iron. Surface morphology, crystal structure, optical and electrical properties of the nanostructures are investigated. X-ray diffraction study shows that the as-prepared powders are amorphous in nature and CaTiO3 phase formation starts at around 500 0C. Rietveld analysis revealed that the particle size of iron substituted CaTiO3 is in nanometer range. Optical bandgap of the nanostructures varies from 4.3 to 3.7 eV for the variation of iron concentration from 0.05 to 0.2 mole %.

The Mechanical Alloying of Magnetite Concentrate with Biochar

2020 ◽  
Vol 10 (2) ◽  
pp. 116-125
Author(s):  
Elif Aranci Öztürk ◽  
Mustafa Boyrazli ◽  
Mehmet Deniz Turan ◽  
Murat Erdemoğlu
Keyword(s):  
Crystal Structure ◽  
Particle Size ◽  
Grain Size ◽  
Mechanical Alloying ◽  
Milled Powder ◽  
Spherical Particles ◽  
Size Analysis ◽  
Biomass Waste ◽  
Magnetic Separator ◽  
Magnetite Concentrate

Aim: In this work, the effect of milling time on the mechanical alloying of the mixture containing the magnetite concentrate and biomass waste was investigated. Materials and Methods: The ore’s grade consisting of hematite and magnetite minerals was increased from 49.87% Fe to 67.29% Fe using the low intensity wet magnetic separator. Biomass waste which was supplied from ÇAYKUR black tea facilities, used as a carbon source was subjected to carbonization processes at 800°C for 1440 min. After the carbonization process, the carbon and sulphur contents of the biomass were measured as 94.68% and 0.03%, respectively. For the mechanical alloying process, a mixture consisting of magnetite concentrate with a grain size of -45 μm and biomass which was added two times the amount of carbon required for the reduction of magnetite to metallic iron was used. Result: After the mechanical alloying process which was carried out at different times, it was observed in the particle size analysis that the particle size of 90% of the mixture was reduced to about 4 μm. In SEM (Scanning Electron Microscopy) images, cube-like particles along with the spherical particles were observed depending on the mechanical alloying times. After 45 minutes of alloying, it was observed that the carbonized product milled together with magnetite concentrate was partially integrated into the crystal structure. Conclusion: The carbonized tea plant waste milled together with magnetite concentrate was partially integrated into the crystal structure. And the mechanical alloying provide to increase in the specific surface area in parallel with the grain size decrease in the study. Thus, in the later stage of the study, the milled powder acquired more ability to react.

Effect of SiO2 Particle Size on Optical Properties of TiO2-SiO2 Nanocomposite Thin Films

2013 ◽  
Vol 684 ◽  
pp. 67-71 ◽  
Author(s):  
Je Hun Kim ◽  
Hyun Goo Choi ◽  
Ting Zhang ◽  
Chul Han Kwon ◽  
Young Ho Kim ◽  
...  
Keyword(s):  
Crystal Structure ◽  
Thin Films ◽  
Particle Size ◽  
Uv Light ◽  
Surface Characteristics ◽  
Dip Coating ◽  
Colloidal Solutions ◽  
Nano Composite ◽  
Glass Substrates ◽  
Dip Coating Technique

TiO2-SiO2thin film system is known to be very attractive to use for photocatalytic and display applications. In this study, TiO2-SiO2nano-composite solutions were prepared by adding colloidal solutions consisted of different SiO2nano-particle sizes (7-50 nm) into TiO2powder-dispersed solutions. TiO2-SiO2thin films on glass substrates were fabricated by the dip-coating technique and their crystal structure, surface morphology and photocatalytic properties were investigated as a function of SiO2particle size. While the SiO2particle size had little influence on the crystal structure of thin films, the photocatalytic activity and anti-reflectance (anti-glare) characteristics were found to be dependent on the SiO2particle size. This result could be explained in terms of surface characteristics and the order of degradation of methylene blue under UV light irradiation.

Preparation and Particle Size Characterization of Cu Nanoparticles Prepared by Anodic Arc Plasma

2010 ◽  
Vol 92 ◽  
pp. 163-169
Author(s):  
Hong Xia Qiao ◽  
Zhi Qiang Wei ◽  
Ming Ru Zhou ◽  
Zhong Mao He
Keyword(s):  
Crystal Structure ◽  
Particle Size ◽  
Specific Surface ◽  
Size Distribution ◽  
Surface Area ◽  
Specific Surface Area ◽  
Average Particle Size ◽  
Spherical Shape ◽  
Average Particle ◽  
Uniform Size

Copper nanoparticles were successfully prepared in large scales by means of anodic arc discharging plasma method in inert atmosphere. The particle size, specific surface area, crystal structure and morphology of the samples were characterized by X-ray diffraction (XRD), BET equation, transmission electron microscopy (TEM) and the corresponding selected area electron diffraction (SAED). The experiment results indicate that the crystal structure of the samples is fcc structure as same as that of the bulk materials. The specific surface area is is 11 m2/g, with the particle size distribution ranging from 30 to 90 nm, the average particle size about 67nm obtained from TEM and confirmed from XRD and BET results. The nanoparticles have uniform size, higher purity, narrow size distribution and spherical shape can be prepared by this convenient and effective method.

Novel Nanohybrids Derived from the Attachment of FePt Nanoparticles on Carbon Nanotubes

2008 ◽  
Vol 8 (11) ◽  
pp. 5942-5951 ◽  
Author(s):  
Theodoros Tsoufis ◽  
Aphrodite Tomou ◽  
Dimitrios Gournis ◽  
Alexios P. Douvalis ◽  
Ioannis Panagiotopoulos ◽  
...  
Keyword(s):  
Crystal Structure ◽  
Carbon Nanotubes ◽  
Particle Size ◽  
Fept Nanoparticles ◽  
Face Centered Cubic ◽  
Magnetization Measurements ◽  
Hybrid Sample ◽  
The Face ◽  
Face Centered ◽  
Mwcnts Surface

Multiwalled carbon nanotubes (MWCNTs) were used as nanotemplates for the dispersion and stabilization of FePt nanoparticles (NPs). Pre-formed capped FePt NPs were connected to the MWCNTs external surface via covalent binding through organic linkers. Free FePt NPs and MWCNTs-FePt hybrids were annealed in vacuum at 700 °C in order to achieve the L10 ordering of the FePt phase. Both as prepared and annealed samples were characterized and studied using a combination of experimental techniques, such as Raman and Mössbauer spectroscopies, powder X-ray Diffraction (XRD), magnetization and transmittion electron microscopy (TEM) measurements. TEM measurements of the hybrid sample before annealing show that a fine dispersion of NPs along the MWCNTs surface is achieved, while a certain amount of free particles attached to each other in well connected dense assemblies of periodical or non-periodical particle arrangements is also observed. XRD measurements reveal that the FePt phase has the face-centered cubic (fcc) disordered crystal structure in the as prepared samples, which is transformed to the face-centered tetragonal (fct) L10 ordered crystal structure after annealing. An increase in the average particle size is observed after annealing, which is higher for the free NPs sample. Superparamagnetic phenomena due to the small FePt particle size are observed in the Mössbauer spectra of the as prepared samples. Mössbauer and magnetization measurements of the MWCNTs-FePt hybrids sample reveal that the part of the FePt particles attached to the MWCNTs surface shows superparamagnetic phenomena at RT even after the annealing process. The hard magnetic L10 phase characteristics are evident in the magnetization measurements of both samples after annealing, with the coercivity of the hybrid sample over-scaling that of the free NPs sample by a factor of 1.25.

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