Microstructure Evolution During Mechanical Alloying of Face Centered Cubic Ti3Si Nanoparticles

2009 ◽  
Vol 6 ◽  
pp. 177-184
Author(s):  
Qiong Wu ◽  
Chang Sheng Li ◽  
Hua Tang ◽  
Xiao Hui Yu ◽  
Ke Sheng Cao ◽  
...  
Keyword(s):  
Mechanical Alloying ◽  
Lattice Parameter ◽  
Face Centered Cubic ◽  
X Ray Diffraction ◽  
X Ray ◽  
Parameter Ratio ◽  
Transmission Electron ◽  
Si Nanoparticles ◽  
Amorphous Compounds ◽  
Face Centered

Face centered cubic Ti3Si nanoparticles were synthesized by mechanical alloying process and the structural and compositional evolutions during the mechanical alloying process were investigated by X-ray diffraction and High Resolution Transmission Electron Microscopy. The results showed that the lattice parameter ratio c/a and the unit cell volume of Ti(Si) were found to decrease with increasing milling time, indicating that the shrinkage of Ti lattice was caused by diffusion of Si atoms into Ti. After milling 51h, amorphous compounds were obtained by alloying Ti and Si powders, and the following mechanical alloying process crystallized the amorphous alloy to crystalline Ti3Si nanoparticles. These nanoparticles were predominantly crystalline with traces of the remnant amorphous phase.

Structural, morphological, and magnetic study of nanocrystalline cobalt-copper powders synthesized by the polyol process

1995 ◽  
Vol 10 (6) ◽  
pp. 1546-1554 ◽  
Author(s):  
G.M. Chow ◽  
L.K. Kurihara ◽  
K.M. Kemner ◽  
P.E. Schoen ◽  
W.T. Elam ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Face Centered Cubic ◽  
X Ray Diffraction ◽  
X Ray ◽  
Transmission Electron ◽  
Copper Powders ◽  
Face Centered ◽  
Increasing Temperature ◽  
X Ray Absorption

Nanocrystalline CoxCu100−x (4 ⋚ x ⋚ 49 at. %) powders were prepared by the reduction of metal acetates in a polyol. The structure of powders was characterized by x-ray diffraction (XRD), transmission electron microscopy (TEM), high resolution transmission electron microscopy (HRTEM), extended x-ray absorption fine structure (EXAFS) spectroscopy, solid-state nuclear magnetic resonance (NMR) spectroscopy, and vibrating sample magnetometry (VSM). As-synthesized powders were composites consisting of nanoscale crystallites of face-centered cubic (fcc) Cu and metastable face-centered cubic (fcc) Co. Complementary results of XRD, HRTEM, EXAFS, NMR, and VSM confirmed that there was no metastable alloying between Co and Cu. The NMR data also revealed that there was some hexagonal-closed-packed (hcp) Co in the samples. The powders were agglomerated, and consisted of aggregates of nanoscale crystallites of Co and Cu. Upon annealing, the powders with low Co contents showed an increase in both saturation magnetization and coercivity with increasing temperature. The results suggested that during preparation the nucleation of Cu occurred first, and the Cu crystallites served as nuclei for the formation of Co.

scholarly journals Development of Ternary and Quaternary Catalysts for the Electrooxidation of Glycerol

2012 ◽  
Vol 2012 ◽  
pp. 1-6 ◽  
Author(s):  
L. M. Artem ◽  
D. M. Santos ◽  
A. R. De Andrade ◽  
K. B. Kokoh ◽  
J. Ribeiro
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Cyclic Voltammetry ◽  
Pechini Method ◽  
Particle Sizes ◽  
Face Centered Cubic ◽  
X Ray Diffraction ◽  
X Ray ◽  
Transmission Electron ◽  
Face Centered

This work consisted in the preparation of platinum-based catalysts supported on carbon (Vulcan XC-72) and investigation of their physicochemical and electrochemical properties. Catalysts of the C/Pt-Ni-Sn-Me (Me = Ru or Ir) type were prepared by the Pechini method at temperature of350∘C. Four different compositions were homemade: C/Pt60Sn10Ni30, C/Pt60Sn10Ni20Ru10, C/Pt60Sn10Ni10Ru20, and C/Pt60Sn10Ni10Ir20. These catalysts were electrochemically and physically characterized by cyclic voltammetry (CV), chronoamperometry (CA) in the presence of glycerol 1.0 mol dm-3, X-ray diffraction (XRD), and high-resolution transmission electron microscopy (HRTEM). XRD results showed the main peaks of face-centered cubic Pt. The particle sizes obtained from XRD and HRTEM experiments were close to values ranging from 3 to 8.5 nm. The CV results indicate behavior typical of Pt-based catalysts in acid medium. The CV and CA data reveal that quaternary catalysts present the highest current density for the electrooxidation of glycerol.

Synthesis and Characterization of Nanocrystalline CeO2

2006 ◽  
Vol 306-308 ◽  
pp. 1103-1108
Author(s):  
Abdul Hadi ◽  
Iskandar Idris Yaacob
Keyword(s):  
Fine Particles ◽  
Gas Adsorption ◽  
Mesoporous Structure ◽  
Face Centered Cubic ◽  
X Ray Diffraction ◽  
X Ray ◽  
Transmission Electron ◽  
Face Centered ◽  
Adsorption Desorption

Nanocrystalline CeO2 has been synthesized at room temperature using water-in-oil (w/o) microemulsion technique. The structure and properties of the nanocrystalline CeO2 were characterized using X-ray diffraction (XRD), transmission electron microscopy (TEM), and gas adsorption desorption measurement. XRD results showed the synthesized CeO2 has a face centered cubic structure with crystallite size of about 5.2 nm. TEM observation also indicated the presence of nanometer sized particles of CeO2. Coarser particles were also observed due to agglomeration. Gas adsorption desorption isotherms showed the behavior of fine particles with mesoporous structure.

scholarly journals Electrochemical and Morphological Investigations of Ga Addition to Pt Electrocatalyst Supported on Carbon

2017 ◽  
Vol 2017 ◽  
pp. 1-15 ◽  
Author(s):  
Giordano T. Paganoto ◽  
Deise M. Santos ◽  
Tereza C. S. Evangelista ◽  
Marco C. C. Guimarães ◽  
Maria Tereza W. D. Carneiro ◽  
...  
Keyword(s):  
Electrochemical Impedance ◽  
Physicochemical Characterization ◽  
Face Centered Cubic ◽  
X Ray Diffraction ◽  
Precursor Method ◽  
Tem Analysis ◽  
X Ray ◽  
Transmission Electron ◽  
Face Centered

This paper is consisted in the synthesis of platinum-based electrocatalysts supported on carbon (Vulcan XC-72) and investigation of the addition of gallium in their physicochemical and electrochemical properties toward ethanol oxidation reaction (EOR). PtGa/C electrocatalysts were prepared through thermal decomposition of polymeric precursor method at a temperature of 350°C. Six different compositions were homemade: Pt50Ga50/C, Pt60Ga40/C, Pt70Ga30/C, Pt80Ga20/C, Pt90Ga10/C, and Pt100/C. These electrocatalysts were electrochemically characterized by cyclic voltammetry (CV), chronoamperometry (CA), chronopotentiometry (CP), and electrochemical impedance spectroscopy (EIS) in the presence and absence of ethanol 1.0 mol L−1. Thermogravimetric analysis (TGA), energy dispersive X-ray spectroscopy (EDX), X-ray diffraction (XRD), and transmission electron microscopy (TEM) were also carried out for a physicochemical characterization of those materials. XRD results showed the main peaks of face-centered cubic Pt. The particle sizes obtained from XRD and TEM analysis range from 7.2 nm to 12.9 nm. The CV results indicate behavior typical of Pt-based electrocatalysts in acid medium. The CV, EIS, and CA data reveal that the addition of up to 31% of gallium to the Pt highly improves catalytic activity on EOR response when compared to Pt100/C.

scholarly journals Evolution of Face-Centered Cubic Ti Alloys Transformation by X-ray Diffraction Profile Analysis in Mechanical Alloying

Metals ◽  
2021 ◽  
Vol 11 (11) ◽  
pp. 1841
Author(s):  
Edgar Pio ◽  
Ariosto Medina ◽  
Carola Martínez ◽  
Felipe Manuel Castro Cerda ◽  
Claudio Aguilar
Keyword(s):  
Mechanical Alloying ◽  
Profile Analysis ◽  
Rietveld Method ◽  
Planetary Mill ◽  
Face Centered Cubic ◽  
X Ray Diffraction ◽  
Diffraction Profile ◽  
X Ray ◽  
Diffraction Patterns ◽  
Face Centered

Four titanium alloys (Ti-Ta, Ti-Ta-Sn, Ti-Ta-Mn, and Ti-Nb-Sn) were synthesized by mechanical alloying (MA) in a planetary mill in different times between 2 h and 100 h. The microstructure characterization was made by X-ray diffraction (XRD), in which the Rietveld method was applied to analyze the diffraction patterns. The study demonstrated that after short milling times between 2 h and 30 h, the fraction of hexagonal close-packed (hcp) phase decreases; at the same time, the formation of body-centered cubic (bcc) and face-centered cubic (fcc) Ti phases are promoted. Additionally, after 30 h of MA, the full transformation of hcp-Ti was observed, and the bcc-Ti to fcc-Ti phase transformation took place until 50 h. The results suggest that the addition of Ta and Sn promotes the fcc-Ti phase formation, obtaining 100% of this phase at 50 h onwards, whereas Nb and Mn show the opposite effect.

Synthesis and Characterization of Silver Nanowires

2013 ◽  
Vol 678 ◽  
pp. 212-216
Author(s):  
Subbaiyan Sugapriya ◽  
Rangarajalu Sriram ◽  
Sriram Lakshmi
Keyword(s):  
Silver Nanowires ◽  
Synthesis And Characterization ◽  
Face Centered Cubic ◽  
Capping Agent ◽  
X Ray Diffraction ◽  
X Ray ◽  
Transmission Electron ◽  
Face Centered ◽  
Fcc Structure

ABSTRACT Silver nanowires have been synthesized by polyol process with ethylene glycol as solvent and PVP as capping agent. The silver nanowires have been characterized by X-ray diffraction (XRD), Scanning electron microscopy (SEM), Energy-dispersive X-ray spectroscopy (EDX), and Transmission electron microscope (TEM) techniques. The prepared silver nanowires were found to exhibit face-centered cubic (fcc) structure. The diameter of the prepared silver nanowires have been found to lie in the range of 60 - 80 nm and the length of the wires have been observed to be in the range of 10-20 µm. The I-V characteristics have been carried out to study the conducting behavior of the prepared silver nanowires.

scholarly journals Synthesis of Ag Nanostructures by Photochemical Reduction Using Citrate-Capped Pt Seeds

2011 ◽  
Vol 2011 ◽  
pp. 1-7 ◽  
Author(s):  
Hyeong-Ho Park ◽  
Xin Zhang ◽  
Yong-June Choi ◽  
Hyung-Ho Park ◽  
Ross H. Hill
Keyword(s):  
Average Diameter ◽  
Uv Exposure ◽  
Face Centered Cubic ◽  
X Ray Diffraction ◽  
Photochemical Reduction ◽  
X Ray ◽  
Transmission Electron ◽  
Visible Spectra ◽  
Uv Visible ◽  
Face Centered

A simple synthesis of Ag nanostructures such as nanorods and nanowires has been demonstrated with citrate-capped Pt seeds. UV-visible spectra and photographs of the synthesized solutions at different UV exposure times showed that the citrate-capped Pt seed played a crucial role in the growth of Ag nanostructures. After UV exposure of the colloidal solution for 60 min, the average diameter, length, and aspect ratio of the Ag nanostructures were about 95 nm, 2.1 μm, and 22, respectively. The photochemical reduction is hypothesized to result from photoelectron transfer from adsorbed citrate to Pt nanoparticle seed allowing Ag ions to form Ag nanostructures. Based on X-ray diffraction spectra and transmission electron microscope images, the synthesized Ag nanostructures were a face-centered cubic single crystal with good purity. These results suggest that the photochemical reduction method can provide Ag nanostructures in the presence of citrate-capped Pt seeds at room temperature for anisotropic Ag products.

Platinum Immobilization on Iron Oxide Nanoparticles Surface under Sonication

2011 ◽  
Vol 183-185 ◽  
pp. 1989-1994
Author(s):  
Quan Guo He ◽  
Zhao Hui Wu ◽  
Rong Hu
Keyword(s):  
Iron Oxide ◽  
Face Centered Cubic ◽  
X Ray Diffraction ◽  
Environment Friendly ◽  
X Ray ◽  
Composite Microspheres ◽  
Selected Area Electron Diffraction ◽  
Transmission Electron ◽  
Face Centered ◽  
Fcc Structure

A facile and environment-friendly sonochemical route to fabricate well-defined Fe3O4/Pt and γ-Fe2O3/Pt composite microspheres under mild conditions has been reported. The structure and morphology of the synthetic spherical-shaped Fe3O4/Pt and γ-Fe2O3/Pt products were characterized by X-ray diffraction (XRD) and transmission electron microscopy (TEM) with selected area electron diffraction (SAED). The results revealed that the composites were spherical with diameter in the range of 50–80 nm and had an ordered face-centered cubic (fcc) structure of platinum. These nanocomposites with platinum-coated iron oxide can be applied in a variety of areas, including medicine, photonics, new functional device assemblies and catalysis especially for fabricating some magnetic-responsive catalyst.

scholarly journals Diffraction studies on Ni–Co and Ni–Cr alloy thin films

1991 ◽  
Vol 6 (4) ◽  
pp. 749-754 ◽  
Author(s):  
A.R. Sethuraman ◽  
R.J. De Angelis ◽  
P.J. Reucroft
Keyword(s):  
Amorphous Structure ◽  
Face Centered Cubic ◽  
Limited Information ◽  
X Ray Diffraction ◽  
Tem Analysis ◽  
Alloy Films ◽  
X Ray ◽  
Cr Content ◽  
Transmission Electron ◽  
Face Centered

Alloy films of Ni–Co and Ni–Cr of compositional ratios 1:1, 1:3, and 3:1 deposited by vapor deposition were studied by Transmission Electron Microscopy (TEM) and X-Ray Diffraction (XRD). Results of TEM analysis on the Ni–Co alloy films indicated that the films were face-centered cubic (fcc) in structure. XRD results confirmed the TEM observations. TEM analysis of Ni–Cr alloy films showed that the films were body-centered cubic (bcc) in structure. With increase in the Cr content more than 25%, the material contained a higher fraction of an amorphous phase. XRD studies provide limited information owing to the quasi-amorphous structure of the films of high Cr content.

scholarly journals Synthesis of Pd-Fe System Alloy Nanoparticles by Pulsed Plasma in Liquid

Nanomaterials ◽  
2018 ◽  
Vol 8 (12) ◽  
pp. 1068 ◽  
Author(s):  
Shota Tamura ◽  
Tsutomu Mashimo ◽  
Kenta Yamamoto ◽  
Zhazgul Kelgenbaeva ◽  
Weijan Ma ◽  
...  
Keyword(s):  
Solid Solution ◽  
Solution Structure ◽  
Lattice Parameter ◽  
Face Centered Cubic ◽  
Pulsed Plasma ◽  
X Ray ◽  
Transmission Electron ◽  
Vegard’S Law ◽  
Face Centered ◽  
Plasma In Liquid

We synthesized Pd-Fe series nanoparticles in solid solution using pulsed plasma in liquid with Pd-Fe bulk mixture electrodes. The Pd-Fe atomic percent ratios were 1:3, 1:1, and 3:1, and the particle size was measured to be less than 10 nm by high-resolution transmission electron microscopy (HR-TEM). The nanoparticles showed face-centered cubic structure. The lattice parameter increased with increasing Pd content and followed Vegard’s law, and energy-dispersive X-ray spectra were consistent with the ratios of the starting samples, which showed a solid solution state. The solid solution structure and local structure were confirmed by HR-TEM and X-ray absorption fine structure.

Sign in / Sign up

Export Citation Format

Share Document