Preparation of Fe Nanoparticles by Confined Arc Plasma Method

2012 ◽  
Vol 476-478 ◽  
pp. 1206-1209
Author(s):  
Xiao Ju Yao ◽  
Zhi Qiang Wei ◽  
Hua Yang ◽  
Li Gang Liu
Keyword(s):  
Particle Size ◽  
Average Particle Size ◽  
Average Particle ◽  
Arc Plasma ◽  
X Ray ◽  
Plasma Method ◽  
Selected Area Electron Diffraction ◽  
Transmission Electron ◽  
Fe Nanoparticles ◽  
Bcc Structure

In the protecting inert gas, Fe nanoparticles were successfully prepared by confined arc plasma method. The particle size, microstructure and morphology of the particles 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). The experiment results indicate that the samples by this process distributed uniform with spherical chain shapes, the crystal structure is body centered cubic (BCC) structure as same as the bulk materials, the particle size distribution ranging from 20 to 70 nm, with an average particle size about 39 nm obtained by TEM and confirmed by XRD and BET results. The specific surface area is 17.5 m2/g.

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.

STRUCTURE AND MAGNETIC PROPERTIES OF CARBON-ENCAPSULATED Fe NANOPARTICLES OBTAINED BY A MODIFIED ARC PLASMA METHOD

2009 ◽  
Vol 23 (17) ◽  
pp. 2149-2153 ◽  
Author(s):  
GUIZHEN WANG ◽  
GENGPING WAN ◽  
CHUNCHENG HAO
Keyword(s):  
Magnetic Properties ◽  
Magnetic Measurements ◽  
Carbon Sources ◽  
Vibrating Sample Magnetometer ◽  
Arc Plasma ◽  
X Ray ◽  
Plasma Method ◽  
Transmission Electron ◽  
Fe Nanoparticles ◽  
Coating Layers

Carbon-encapsulated Fe nanoparticles were synthesized by a modified arc plasma method using methane and starch as carbon sources, respectively. The particles were characterized in detail by transmission electron microscope and X-ray powder diffraction. They are somewhat spherical in shape and the coating layers of the two sample types are composed of amorphous carbon. Magnetic measurements using a vibrating sample magnetometer demonstrate that the prepared composites have different magnetic properties.

A powder x-ray diffraction study of a solution treated and ice brine quenched Al–14.25 at.% Li alloy

1991 ◽  
Vol 6 (4) ◽  
pp. 712-718 ◽  
Author(s):  
A.G. Fox ◽  
S.C. Fuller ◽  
C.E. Whitman ◽  
V. Radmilovic
Keyword(s):  
Particle Size ◽  
Volume Fraction ◽  
Average Particle Size ◽  
Average Particle ◽  
X Ray Diffraction ◽  
Maximum Order ◽  
X Ray ◽  
Order And Disorder ◽  
Solution Treated ◽  
Transmission Electron

An x-ray diffractogram was generated from a powder sample of solution treated and ice brine quenched Al–14.25 at.% Li alloy. The Bragg reflections obtained were characteristic of a very-nearly fully ordered Al-rich L12 phase based on δ'Al3Li together with two very weak reflections associated with δAlLi. All the lines were significantly broadened due to particle size effects. The average particle size associated with the 100 L12 superlattice line was found to be 4.2 (3) nm and with the fundamental lines, 26.8 nm. A simple structure factor calculation indicated the volume fraction of ordered phase to be around 0.77, assuming that the lack of maximum order was due to the presence of disordered fcc AlLi solid solution. These results suggest that the microstructure of this as-quenched alloy comprises ordered regions of about 4 nm in size in a sea of disordered matrix with a very small amount of δAlLi present. This conclusion is in excellent agreement with recent small angle x-ray and transmission electron microscope studies on similar alloys and suggests that AlLi alloys which are ostensibly disordered at high temperatures go through a disorder-order transformation and then decompose into regions of order and disorder which are associated with a composition spinodal.

Synthesis and Characterization of Strontium and Calcium Titanate Polycrystalline Powders by a Modified Polymeric Precursor Technique

2012 ◽  
Vol 727-728 ◽  
pp. 904-908
Author(s):  
R. Muccillo ◽  
J.R. Carmo
Keyword(s):  
Particle Size ◽  
Structural Phase ◽  
Average Particle Size ◽  
Calcium Titanate ◽  
Average Particle ◽  
Polymeric Precursor ◽  
X Ray Diffraction ◽  
Laser Scattering ◽  
X Ray ◽  
Transmission Electron

SrTi0,65Fe0,35O3-δ, Ca0,5Sr0,5Ti0,65Fe0,35O3-δ, CaTi0,65Fe0,35O3-δceramic powders were synthesized by the polymeric precursor technique using CaCO3, SrCO3, C12H28O4Ti and Fe (NO3)3.9H2O. After calcination, each powder was heat treated at temperatures chosen according to data collected on thermogravimetric-differential thermal analysis experiments. The compositions were analyzed by X-ray diffraction for structural phase evaluation (either perovskite cubic or orthorhombic), laser scattering for determination of particle size distribution and average particle size, transmission electron microscopy (TEM) for observation of particle shape and average true size. Pressed powders sintered at 1250°C were analyzed by X-ray diffraction and X-ray fluorescence; their surfaces were observed by scanning probe microscopy (SPM) for topographical analysis of grains and grain boundaries. TEM results show that the powders consist of agglomerated nanoparticles. Sr-based compounds have cubic perovskite phases whereas Ca-based compounds are orthorhombic. SPM images show intergranular features which might be responsible for reported blocking of charge carriers observed in impedance spectroscopy diagrams.

Mn and MnZn Ferrite Powders Prepared by Detonation of Emulsion Explosives

2011 ◽  
Vol 694 ◽  
pp. 630-634
Author(s):  
Xiao Jie Li ◽  
Xiao Hong Wang ◽  
Hong Hao Yan ◽  
Li Xue ◽  
Ning Luo
Keyword(s):  
Particle Size ◽  
Average Particle Size ◽  
Residual Magnetization ◽  
Average Particle ◽  
Vibrating Sample Magnetometer ◽  
X Ray Diffraction ◽  
Emulsion Explosives ◽  
Mnzn Ferrite ◽  
X Ray ◽  
Transmission Electron

In the present work, nano Mn and MnZn ferrite powders were prepared by detonation of emulsion explosives, XRD(X-ray diffraction),TEM(transmission electron microscope) and VSM(vibrating sample magnetometer) experiments were carried out respectively to characterize and research the prepared powders. Results indicated that the average particle size of the raw Mn and MnZn ferrite powders was around 30nm, and Zn2+ seriously destroyed and reduced the dispersity and homogeneity of the powders although they were successfully doped in nano-Mn ferrite crystals. The average particle size, the specific residual magnetization(σr) and the coercivity(Hc) of the powders were all decreased with the increasing of the hexogen(for short, RDX) content.

Physical Properties of Nanocrystalline MoS2 and WS2 Particles Produced by CO2 Laser Pyrolysis

1993 ◽  
Vol 327 ◽  
Author(s):  
Xiang-Xin Bi ◽  
Ying Wang ◽  
W. T. Lee ◽  
Kai-An Wang ◽  
S. Bandow ◽  
...  
Keyword(s):  
Particle Size ◽  
Structural Phase ◽  
Average Particle Size ◽  
Nanocrystalline Powders ◽  
Average Particle ◽  
X Ray Diffraction ◽  
X Ray ◽  
Laser Pyrolysis ◽  
Transmission Electron ◽  
Size Crystallite

AbstractNanocrystalline powders of 2H-MoS2 and 2H-WS2 with average particle size 5 and 9 nm, respectively, have been produced using C02laser pyrolysis. Typical production rate for these nanoparticles is 2g/hr. Particle size, crystallite size, and the structural phase were determined using X-ray diffraction(XRD), transmission electron microscopy(TEM), and Raman scattering. Particle size effects may have been observed in the Raman-active modes (WS2 and MoS2) and in the band-edge excitons (MoS2).

SYNTHESIS AND CHARACTERIZATION OF TITANIUM DIOXIDE DOPED WITH Sc3+ IONS

2006 ◽  
Vol 05 (02n03) ◽  
pp. 351-357 ◽  
Author(s):  
YOUNG SOO KANG ◽  
DONG RI ZHANG
Keyword(s):  
Titanium Dioxide ◽  
Anatase Phase ◽  
Sol Gel ◽  
Average Particle Size ◽  
Average Particle ◽  
X Ray ◽  
Selected Area Electron Diffraction ◽  
Transmission Electron ◽  
Ft Ir ◽  
Xrd Patterns

Nanoparticles of titanium dioxide ( TiO 2) doped with 5 at.% Sc 3+ ions were synthesized using the sol–gel method and calcined at 500°C to obtain better anatase phase. The crystal structures of the doped TiO 2 nanoparticles were characterized by X-ray powder diffraction (XRD), Raman, UV-vis, FT-IR spectroscopy, high resolution transmission electron microscopy (HRTEM) and selected-area electron diffraction (SAED). XRD patterns and Raman spectra of TiO 2 + 5 at.% Sc -500°C show the anatase phase and the average particle size of the sample calculated from XRD patterns was determined as 5.9 nm. Well-resolved rings of SAED of TiO 2 doped with Sc 3+ ions are easily indexed to those from XRD pattern. HRTEM shows the well-defined lattice fringes and the lattice spacing measured from HRTEM is 0.33 nm, which is in well agreement with the distance between the (101) planes in anatase TiO 2. Energy-dispersive X-ray (EDX) spectrum of the doped TiO 2 confirms the presence of Sc element in the TiO 2 matrix.

A novel organothermal reduction process for producing nanocrystalline Ni2P with a circular-shaped flake morphology

1998 ◽  
Vol 13 (12) ◽  
pp. 3365-3367 ◽  
Author(s):  
Shu-Hong Yu ◽  
Jian Yang ◽  
Yong-Sheng Wu ◽  
Zhao-Hui Han ◽  
Lei Shu ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Particle Size ◽  
Powder Diffraction ◽  
Average Particle Size ◽  
Reduction Process ◽  
Average Particle ◽  
X Ray ◽  
Transmission Electron ◽  
A Cell

An organothermal reduction process has been successfully developed for synthesis of nanocrystalline Ni2P in benzene at 140 °C. An x-ray powder diffraction pattern (XRD) indicated that the product was pure hexagonal Ni2P phase with a cell constants a =0.5866 and c = 0.3377 nm. Transmission electron microscopy (TEM) showed that the average particle size of the powders was 40 nm with a circular-shaped flake morphology.

scholarly journals Thermal, Structural, and Physical Properties of Freeze Dried Tropical Fruit Powder

2014 ◽  
Vol 2014 ◽  
pp. 1-10 ◽  
Author(s):  
K. A. Athmaselvi ◽  
C. Kumar ◽  
M. Balasubramanian ◽  
Ishita Roy
Keyword(s):  
Particle Size ◽  
Physical Properties ◽  
Average Particle Size ◽  
Average Particle ◽  
X Ray Diffraction ◽  
Tropical Fruit ◽  
X Ray ◽  
Freeze Dried ◽  
Fruit Powder ◽  
Lcr Meter

This study evaluates the physical properties of freeze dried tropical (guava, sapota, and papaya) fruit powders. Thermal stability and weight loss were evaluated using TGA-DSC and IR, which showed pectin as the main solid constituent. LCR meter measured electrical conductivity, dielectric constant, and dielectric loss factor. Functional groups assessed by FTIR showed presence of chlorides, and O–H and N–H bonds in guava, chloride and C–H bond in papaya, and chlorides, and C=O and C–H bonds in sapota. Particle size and type of starch were evaluated by X-ray diffraction and microstructure through scanning electronic microscopy. A semicrystalline profile and average particle size of the fruit powders were evidenced by X-ray diffraction and lamellar/spherical morphologies by SEM. Presence of A-type starch was observed in all three fruits. Dependence of electric and dielectric properties on frequency and temperature was observed.

Synthesis and Characterization of Water-Soluble Monolayer-Protected Gold Nanoparticles

2011 ◽  
Vol 415-417 ◽  
pp. 617-620 ◽  
Author(s):  
Yan Su ◽  
Ying Yun Lin ◽  
Yu Li Fu ◽  
Fan Qian ◽  
Xiu Pei Yang ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Particle Size ◽  
Gold Nanoparticles ◽  
Average Particle Size ◽  
Water Soluble ◽  
Synthesis And Characterization ◽  
Average Particle ◽  
Transmission Electron

Water-soluble gold nanoparticles (AuNPs) were prepared using 2-mercapto-4-methyl-5- thiazoleacetic acid (MMTA) as a stabilizing agent and sodium borohydride (NaBH4) as a reducing agent. The AuNPs product was analyzed by transmission electron microscopy (TEM), UV-vis absorption spectroscopy and Fourier transform infrared spectroscopy (FTIR). The TEM image shows that the particles were well-dispersed and their average particle size is about 5 nm. The UV-vis absorption and FTIR spectra confirm that the MMTA-AuNPs was stabilized by the carboxylate ions present on the surface of the AuNPs.

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