scholarly journals Hydrothermal Synthesis of Leaf-Shaped Ferric Oxide Particles

2009 ◽  
Vol 6 (s1) ◽  
pp. S280-S286
Author(s):  
Keqiang Ding
Keyword(s):  
Ferric Oxide ◽  
Hydrothermal Process ◽  
Potassium Ferricyanide ◽  
X Ray Diffraction ◽  
X Ray ◽  
Oxide Particles ◽  
Ferric Oxides ◽  
Diffraction Patterns ◽  
First Time ◽  
Scanning Electron

For the first time, leaf-shaped ferric oxide particles were prepared from an aqueous solution of potassium ferricyanide [K3Fe(CN)6] by hydrothermal process. Images obtained from SEM (scanning electron microscope) revealed that leaf-shaped ferric oxides (around 1.5 μm in length) were clearly exhibited when the hydrothermal tempreature was 150°C, while as the temperature was increased to 200°C leaf-shaped ferric oxide particles with larger size were observed. XRD (X-ray diffraction) patterns testified that the obtained ferric oxides were α-Fe2O3with well-structured crystal faces. Interestingly, histograms describing the distribution of samples indicated that the distribution of obtained ferric oxide particles did not accord with gaussian distribution

SIZE-INDUCED EFFECTS IN NANOSTRUCTURED NiFe2O4

2010 ◽  
Vol 24 (30) ◽  
pp. 5973-5985
Author(s):  
M. GUNES ◽  
H. GENCER ◽  
T. IZGI ◽  
V. S. KOLAT ◽  
S. ATALAY
Keyword(s):  
Electron Microscopy ◽  
Annealing Temperature ◽  
Structural Parameters ◽  
Hydrothermal Process ◽  
Lattice Parameter ◽  
Effect Of Temperature ◽  
Vibrating Sample Magnetometer ◽  
X Ray Diffraction ◽  
X Ray ◽  
Scanning Electron

NiFe 2 O 4 nanoparticles were successfully prepared by a hydrothermal process, and the effect of temperature on them was studied. The particles were annealed at various temperatures ranging from 413 to 1473 K. Studies were carried out using powder X-ray diffraction, scanning electron microscopy, infrared spectroscopy, differential thermal analysis, thermogravimetric analysis and a vibrating sample magnetometer. The annealing temperature had a significant effect on the magnetic and structural parameters, such as the crystallite size, lattice parameter, magnetization and coercivity.

Sintering AlN Ceramics Below 1500°C with MgO-CaO-Al2O3-SiO2 Glass Addition

2007 ◽  
Vol 336-338 ◽  
pp. 1868-1871 ◽  
Author(s):  
Cheng Fu Yang ◽  
Chien Min Cheng ◽  
Ho Hua Chung ◽  
Chao Chin Chan
Keyword(s):  
Sintering Temperature ◽  
Sol Gel ◽  
X Ray Diffraction ◽  
Dielectric Characteristics ◽  
Sintering Aid ◽  
Glass Addition ◽  
X Ray ◽  
Crystal Phases ◽  
Diffraction Patterns ◽  
Scanning Electron

5~15 wt% MgO-CaO-Al2O3-SiO2 (MCAS, fabricated by sol-gel method) glass is used as the sintering aid of AlN ceramics. The sintering is proceeded from 1350oC~1550oC, scanning electron microscope is used to observe the sintered morphologies and X-ray diffraction pattern are used to confirm the crystal structures. From the SEM observations, as 10wt% and 15wt% MCAS is added, AlN ceramics can be densified at 1500oC and 1450oC, which are much lower than the before studies were. From the X-ray diffraction patterns, the crystal phases of MCAS-AlN ceramics are AlN, Al2O3, and cordierite phases. In this study, the dielectric characteristics of MCAS-AlN ceramics are also developed as a function of MCAS content and sintering temperature.

Effect of FLiBe Infiltration Pressure on Microstructure of Matrix for TMSR Fuel Elements (FEs)

2017 ◽  
Vol 373 ◽  
pp. 189-192
Author(s):  
Hong Xia Xu ◽  
Jun Lin ◽  
Yu Chen ◽  
Bing Chuan Gu ◽  
Bang Jiao Ye ◽  
...  
Keyword(s):  
Positron Lifetime ◽  
X Ray Diffraction ◽  
X Ray ◽  
Positron Annihilation Lifetime ◽  
Infiltration Pressure ◽  
Matrix Graphite ◽  
The Matrix ◽  
Diffraction Patterns ◽  
Fuel Elements ◽  
Scanning Electron

The matrix graphite of fuel elements (FEs) with infiltration of 2LiF-BeF2(FLiBe) at different pressures varying from 0.4 MPa to 1.0 MPa, has been studied by X-ray diffraction (XRD), scanning electron microscope (SEM) and positron annihilation lifetime (PAL) measurement. The result of XRD reveals that diffraction patterns of FLiBe appear in matrix graphite infiltrated with FLiBe at a pressure of 0.8 MPa and 1.0 MPa. The surface morphology from SEM shows that FLiBe mainly distributes within macro-pores of matrix graphite. PAL measurement indicates that there are mainly two positron lifetime components in all specimens:τ1~0.21 ns and τ2 ­~0.47 ns, ascribed to annihilation of positrons in bulk and trapped-positrons at surface, respectively. The average positron lifetime decreases with infiltration pressure, due to the decrease in annihilation fraction of positrons with surface after infiltration of FLiBe into macro-pores.

Effect of the Dwell Temperature on Spark Plasma Sintered CaCu3Ti4O12

2012 ◽  
Vol 727-728 ◽  
pp. 982-987
Author(s):  
E. de Carvalho ◽  
Marcelo Bertolete ◽  
Izabel Fernanda Machado ◽  
E.N.S. Muccillo
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Lattice Parameter ◽  
Solid State Reactions ◽  
X Ray Diffraction ◽  
X Ray ◽  
Plasma Sintering ◽  
Spark Plasma ◽  
Diffraction Patterns ◽  
Scanning Electron

Polycrystalline CaCu3Ti4O12 ceramics were prepared by solid state reactions by spark plasma sintering (SPS) technique. In this study, the effects of the dwell temperature on structural, microstructural and dielectric properties of CaCu3Ti4O12 ceramics have been investigated. Powder mixtures were calcined at 900°C for 18 h before SPS consolidation. The dwell temperatures were 850, 900, 915 and 930°C. Sintered pellets were characterized by X-ray diffraction, scanning electron microscopy and impedance spectroscopy. X-ray diffraction patterns show evidences of a single-phase perovskite-type structure. The calculated lattice parameter is 7.40 Å. The hydrostatic density increases slightly with increasing dwell temperature. Scanning electron microscopy observations revealed a heterogeneous microstructure for all samples. The dielectric loss remains constant over a wide temperature range. The obtained permittivity is approximately 103 at 1 kHz. The increase of the dwell temperature is found to produce a brittle ceramic.

Synthesis, Structural Characterization and Morphological Studies of Nanocrystalline CdO by Wet-Chemical Method

2018 ◽  
Vol 24 (8) ◽  
pp. 5519-5522
Author(s):  
Israr Ul Hassan ◽  
Liji John ◽  
R. Selwin Joseyphus ◽  
I. Hubert Joe ◽  
R. S Amritha ◽  
...  
Keyword(s):  
Grain Size ◽  
Chemical Method ◽  
Cadmium Oxide ◽  
X Ray Diffraction ◽  
Wet Chemical Method ◽  
X Ray ◽  
Morphological Studies ◽  
Oxide Particles ◽  
Wet Chemical ◽  
Scanning Electron

Synthesis of nanocrystalline cadmium oxide particles were explored by the reaction of inorganic precursor (cadmium chloride) and alkali (sodium hydroxide) via modified wet-chemical method followed by annealing at various temperatures (250, 500 and 750 °C). The structural, optical and morphological studies of cadmium oxide samples were carried out by X-ray diffraction, infrared, ultraviolet-visible, and scanning electron microscope techniques. From X-ray diffraction analysis, it was confirmed that cadmium oxide particles furnish a face centred cubic phase structure and revealing a grain size of around 59 nm. The scanning electron microscope micrographs admit that cadmium oxide samples are agglomerated and have spherical shapes. The bonding deformation and stretching frequency results of cadmium oxide samples were obtained from infrared spectra. The corresponding increase in calcination temperatures has shown an increase in particle size while as no change was found in band gape. These results attribute that the variation in annealing temperature has a significant role on the crystalline nature, grain size and its optical properties. Furthermore, the synthesized cadmium oxide samples were examined for bioactivity analysis.

Blue Upconversion Luminescence Properties of La2(WO4)3:Yb3+/Tm3+Phosphor

2011 ◽  
Vol 399-401 ◽  
pp. 1020-1025
Author(s):  
Jin Sheng Liao ◽  
Hang Ying You ◽  
Qing Xia Wu ◽  
He Rui Wen ◽  
Jing Lin Chen ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Upconversion Luminescence ◽  
Hydrothermal Process ◽  
Pumping Power ◽  
X Ray Diffraction ◽  
X Ray ◽  
Laser Pumping ◽  
Upconversion Mechanism ◽  
Upconversion Emissions ◽  
Scanning Electron

Monoclinic La2(WO4)3 nanophosphors codoped with Tm3+ and Yb3+ ions were synthesized via hydrothermal process followed by heat treatment. Powder X-ray diffraction (XRD) and scanning electron microscopy (SEM) were used to characterize as-prepared samples. The dependences of Yb3+/ concentration and laser pumping power on the upconversion emissions were extensively investigated. The results show that upconversion luminescence increases with the Yb3+/ concentration and gets its peak at 30 %. The upconversion mechanism and process in the Yb3+/Tm3+ codoped La2(WO4)3 phosphors were analysed.

Hydrothermal Synthesis and Electrocatalytic Property for H2O2 Reduction of Co3O4 Nanocubes

2011 ◽  
Vol 311-313 ◽  
pp. 477-480
Author(s):  
Zhi Ai Yang ◽  
Li Jin Feng ◽  
Xia Wang ◽  
Rong Ma ◽  
Jian Ping Sun ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Hydrothermal Process ◽  
Linear Sweep Voltammetry ◽  
Average Crystallite Size ◽  
X Ray Diffraction ◽  
Linear Sweep ◽  
Electrocatalytic Property ◽  
X Ray ◽  
Transmission Electron ◽  
Scanning Electron

Subscript textThe Co3O4 nanocubes were synthesized by hydrothermal process. The products are characterized in detail by multiform techniques: scanning electron microscopy, transmission electron microscopy, X-ray diffraction, and energy-dispersive X-ray analysis. The results show that the products are uniform nanocubes with an average crystallite size about 20-40 nm. Electrocatalytic property of the prepared Co3O4 nanocubes was characterized by linear sweep voltammetry. LSV results indicate that Co3O4 nanocubes exhibit a remarkable electrocatalytic activity for the H2O2 reduction.

scholarly journals Synthesis and Catalase Mimic Activity of MnO2 Nano Powder Prepared by Hydrothermal Process

2019 ◽  
Vol 27 (2) ◽  
pp. 228-237 ◽  
Author(s):  
Rashed T. Rasheed ◽  
Sariya D. Al-Algawi ◽  
Rosul M. N.
Keyword(s):  
Crystal Structure ◽  
Electron Microscopy ◽  
Annealing Temperature ◽  
Hydrothermal Process ◽  
X Ray Diffraction ◽  
X Ray ◽  
Nano Powder ◽  
Atomic Force ◽  
Different Temperatures ◽  
Scanning Electron

Manganese dioxide (MnO2) nanopowder has been synthesized by hydrothermal method. MnO2 was annealed at different temperatures (250, 400, 550, 700˚C). The crystal structure and surface morphology of these nanostructures were characterized by X-ray diffraction (XRD), Atomic Force Microscope (AFM) and Scanning Electron Microscopy (SEM). The catalase mimic activity (catalytic activity) of MnO2 against hydrogen peroxide (H2O2) was studied by using the new method and found that 400˚C is the best annealing temperature.

Effects of montmorillonite nanoclay on the properties of chemimechanical pulping paper

BioResources ◽  
2021 ◽  
Vol 16 (3) ◽  
pp. 6281-6291
Author(s):  
Jafar Ebrahimpour Kasmani ◽  
Ahmad Samariha
Keyword(s):  
Tensile Strength ◽  
Morphological Properties ◽  
X Ray Diffraction ◽  
Cationic Starch ◽  
Burst Strength ◽  
X Ray ◽  
Air Resistance ◽  
Diffraction Patterns ◽  
Montmorillonite Nanoclay ◽  
Scanning Electron

The effects of nanoclay were studied relative to the physical, mechanical, optical, and morphological properties of chemimechanical pulping papers. Nanoclay was incorporated at 0%, 2%, 4%, 6%, 8%, or 10%. To increase the retention, 1% cationic starch was used in all test papers. Handsheets (60 g/m2 in weight) were tested to determine their physical, mechanical, optical, and morphological properties. Up to 2% nanoclay increased the tensile strength; at values greater than 2%, the tensile strength decreased. The addition of up to 4% nanoclay increased roughness; between 4% and 10% nanoclay, roughness decreased. With 10% nanoclay, the tear strength, burst strength, and brightness decreased, but the air resistance, opacity, and yellowness increased. Scanning electron microscopy showed that the nanoclay filled the pore spaces between fibers, thus increasing air resistance. X-ray diffraction patterns indicated an intercalated structure.

Synthesis of Ni-Mo-W Sulfide Nanorods as Catalyst for Hydrodesulfurization of Dibenzothiophene

2008 ◽  
Vol 8 (12) ◽  
pp. 6406-6413 ◽  
Author(s):  
F. Paraguay-Delgado ◽  
R. García-Alamilla ◽  
J. A. Lumbreras ◽  
E. Cizniega ◽  
G. Alonso-Núñez
Keyword(s):  
Electron Microscopy ◽  
Physical Adsorption ◽  
Atomic Ratio ◽  
X Ray Diffraction ◽  
X Ray ◽  
Oxide Precursor ◽  
Transmission Electron ◽  
Adsorption Of Nitrogen ◽  
Diffraction Patterns ◽  
Scanning Electron

Two trimetallic sulfurs, MoWNiS and MoWSNi, were synthesized to be used as a catalyst in hydrodesulfurization reactions. The mixed oxide mesoporous nanostructured MoO3-WO3 with an Mo:W atomic ratio of 1:1 was used as the precursor. The first catalyst was prepared by impregnating nickel in the oxide precursor and then subsequent sulfiding with an H2S/H2 mix at 400 °C for 2 hours. The second catalyst was prepared by sulfiding the precursor and then impregnating the nickel, and finally reducing the material with a H2/N2 at 350 °C. In both catalysts the Mo:W:Ni atomic ratio was maintained at 1:1:0.5. The materials obtained were characterized by physical adsorption of nitrogen, X-ray diffraction, scanning electron microscopy, transmission electron microscopy. Furthermore, the materials obtained were evaluated by a dibenzothiophene hydrodesulfuration reaction. The diffraction patterns show that both materials are polycrystalline and mainly of MoS2 and WS2 phases.

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